/I IN MEMORIAM FLORIAN CAJORl c^^ Oc.i<- ■ — '^ ^ }(?} '>^ Digitized by the Internet Archive in 2008 with funding from IVIicrosoft Corporation http://www.archive.org/details/exercisesinalgebOOrobbrich EXERCISES IN ALGEBHA BY EDWARD R. ROBBINS M AND FREDERICK H. SOMERVILLE WILLIAM PENN CHARTER SCHOOL, PHILADELPHIA NEW YORK •:• CINCINNATI •:• CHICAGO AMERICAN BOOK COMPANY Copyright, 1904, by EDWARD R. BOBBINS and FREDERICK H. SOMERVILLE. Enteeed at Stationers' Hall, London. K. A 8. EXERCISES IN ALG. W. P. I Tit. PEEFACE The present-day teacher of Algebra has little time for the selection, from proper sources, much less for the making, of suitable examples often necessary to supplement those con- tained in the standard text-books. This little book is designed to meet the requirements of those teachers who feel such extra assignments in Algebra essential to thorough familiarity with its processes. The aim has been to provide, as compactly as possible, a series of exercises that conform in arrangement with the order of the leading text-books, and that both in degree of difficulty and in scope shall include the work prescribed by high schools and academies, as well as university and college entrance requirements. The plan has been to avoid all examples of more than aver- age difficulty, and to lay particular stress upon those subjects that stand so clearly as the foundations of later work. With this in view, much emphasis has been given to the subjects of Factoring, Fractions, Exponents, Equations, and Logarithms. There has been constant effort to present abundant drill in topics in the mastering of which students seem to have the greatest difficulties. Not only must the pupil who is to master the science solve a multitude of exercises differing in degree rather than in S 4 PREFACE kind, but he must also be taught to select appropriate methods for each of a miscellaneous collection, differing in kind rather than in degree. To this end the book is generously provided with reviews, and the pupil is obliged to discriminate among different kinds of examples — a phase of mathematical train- ing which will be invaluable to him in subsequent study. Furthermore, the reviews are so arranged that they could, if desired, be used independently of the other exercises in final review, or in final preparation for college examinations. The authors will welcome and will appreciate any sugges- tions or corrections from other teachers of Algebra. EDWARD R. ROBBINS. FREDERICK H. SOMERVILLE. Philadelphia, Pa. CONTENTS PAOK Substitution 7 Addition 9 Subti'action 10 Use of the Parenthesis 13 Review 16 Multiplication 17 Division 18 Multiplication by Inspection 20 Division by Inspection 23 Use of the Parenthesis with Multiplication 25 Simple Equations 26 Problems in Simple Equations 27 Review 29 Factoring 31 Review . 38 Highest Common Factor and Lowest Common Multiple . . 40 Fractions : Transformations 42 Addition and Subtraction .45 Multiplication and Division 48 Complex Fractions 50 Fractional Equations : Numerical Equations 55 Literal Equations 59 Simultaneous Equations : Numerical Equations 61 Literal Equations 64 Three or More Unknown Quantities 66 Problems in Simultaneous Equations 68 6 6 CONTENTS Involution and Evolution : Monomials 71 Involution — Binomials 72 Evolution — Square Root .72 Evolution — Cube Root 74 Evolution — Numerical . . . . . . . .74 Review 7G Exponents : Transformations 81 Miscellaneous Applications . 88 Radicals : Transformations . . .93 Miscellaneous Applications 99- Imaginaries 103 General Review . . 107 Quadratic Equations : Numerical Quadratics 116 Literal Quadratics 119 Equations in Quadratic Form 121 Simultaneous Quadratics 123 Properties of Quadratics 126 Ratio and Proportion . . . 129 Variation 132 Arithmetical Progression 134 Geometrical Progression 138 Permutations and Combinations 142 Binomial Theorem 145 Logarithms 148 General Review 156 SUBSTITUTION Exercise 1 Find the numerical value of the following : When a = 1, 6 = 2, c = 3, d = 4. 1. a + b. 10. 7b-(c + d), 2. a + & + c. 11. a + ab. 3. a-f26 + 3c. 12. 3a6-c. 4. a + 36 — d 13. 12a — 3c + cd 5. 2 a 4- 4 6 — 2d 14. 3a + &(a + c). 6. 6a — 6 — d 15. ab-}-a{2b — a). 7. 10c-56 + 2d 16. 4a6c-3(c + d). 8. 3a + c + d 17. a(a + b + c). 9. 3a4-(c4-d)- 18. a6(a + 6 + c). 19. a6(d-a)4-&c(c?-6). 20. a + ab(b + c)-c(3d-3c), 21. c2-|-a6. 25. ab^d - a(b^ -^ c). 22. 62 4.c2 + cZ2. 26. 25d-a62(a + 6 + c). 23. 2a'b^ + Sb^-G' + d. 27. a + (a + 6)1 24. &V + 6c2 + d 28. 4 6cd + (2 6 + c)2. 29. 3(a + 2)2-2(62_l) + 3a26c2. 30. 2(a-{-by-S(d-by-bc{c-hd). When a = 5, b =4:, 31. V6 + Ve. 32. Vie— V2d. SUBSTITUTION c = S, d = 2, e = 9. 33. 34. V5 ab + V4 6. V3 ce — V3 6c. 35. •y/abc 4- 6. 37. Va^ 4- 6' + 8. 38. V2c2 + 3d2-a. 39. a + b -Vbcd -f 1. 40. (a + 6)V6cd + l. 36. -Vabc — Sc — d. 41. (ad — e) V 3 ac — e. 42. (a + Ve)-(e- V6). When a = 4, 6 = = 5, m = 6, n = 10. 43. ^« m 19 3a + 26 n — 1 44 ^ + ^ 2a 3 a + (w — -wi) * 2(n-a) 45. ^(^^-^). a 51. ^4-^ + ^. m n 46. ^(^ + ^) . a6 b n 2a 47. m-\-n — g m / V2a6 + am\ , oo. I ; ]-T ^n — m. \ m + n J 48. ^(^-^) . Whena; = i 2/ = |, 55. iC+2/ + ^- 56. 2x — y — z. 57. a;(x + ?/). 58. 2/ (2 a; — 2;). 54. ^m ^n—m Via + V3 2; = 59. {x-[-y){y-z). 60. aJ2/(a;+?/-2;). 61. {x + lf-{y^-iyH^ + iy. 62. aJ + 2/ ("J- (0^ + ^)^. ADDITION y When a = 4, 6=5, m = 2, w = 3. 63. or. 68. (a + 6)" — (a + 6)"*. 64. a'^ + 6". 69. (26-a)~-(36-a)'". 65. a^' — b'^. 70. (a + 6 — 7)"'. 66. 2a'' + 3a"'b\ 71. (a'^ + ft"')". 67. (a + 6)"'. 72. a~ + a'"(6 - a)". ADDITION Ii2:ercise 2 1. Find the sum ofa + 36 + c, 2a4-76 + 2c, and 3 a + 2 6 + c. 2. Find the sum of 4a + 36 — c, 2a4-264-4c, and a — 3 6 -2 c. 3. Findthesumof 10a-36-2c-d, -2a + 4:b-\-c + Sd, and c — 3 d + a. 4. Add 3a + 26-3c, 12a-46-7c, and 4a-86 + 9c. 5. Add 3a^ + 2a^-2« + ll, 4.a^-2x^-\-3x-S, 4.a^-2x' -\-x-2, -12ar^ + a;2-x-l, and 2 o^ -\- oF - x -\- IS. 6. Collect 5a-3c + 4/-m + 26-d + 4c-2a-3/+c + 2 m + d. 7. Collect 2 a6 4- 3 6c + 4 cd — 2 6c + 3 a6 — 3 cd — 4 a6 - 2 6c-2cd 8. Collect 2a6cd + 3 6fljH-m — 3a6cc2 4-2 6a; — 3m + 6a6cd — 3 6» + 3 m. 9. Collect a^-hSa^ + Sa, a^ + a + l, and 2a + 2. 10. Collect a^ + a'b-\-ab% 3a^ + a'b^-2b% and 4a62-3 6^ 10 SUBTRACTION 11. Arrange in descending powers of x and collect a:^ — 2 + ^x'-x, -a;4-3a^-2ar*, _4ar' + 5a^-a;4- 10, -a;-f4a^- 2 + ic8, and a^ + a;^ _,_ ^ _,_ ^^ 12. Arrange in ascending powers of a and add a^ — 4 a^4- 2a-8, a^ + a-3a2 + 16, a34-a'-2 + 3a, and -^.a' + Qa? + 10 a - 3. 13. Find the sum ofa^-l+3a;-a^ + 2a;-3a:3 + 44-«^- 8a; + 2a.'^ — 4a^ + 10 — ic^, and arrange the answer in descend- ing powers of x. 14. Add 3(a4-6)4-4(c + d)-5(w4-n), 2(a + &)-2(c + c?) -\-Q{m-\- n), and — 4 (a + 6) — (c + d) — (m + n). 15. 16. 17. 18. O/C ac mx my be c 5x -Sy {a-\-b)c (a + l)c ( )» ( )y 19. Add ab + cc? and mb + ncZ. 20. Add ax + by and ca; + dy. 21. Add 2 a6 + 3 c 4- c? and 3 6 + oc + nd 22. Add 3a6+2ac+w, 36— 3ac+mw, and 2 nib +4: be— pn. 23. Add (a + &)c + (6 4- (^)c. 24. Add (m + 7i) a; + (m — n) a; — mx. 25. Add (2 + a)a^ + (3a-4)a^+(a-l)ar^-4aar^. Subtract : 1. 2. 3. 10 a 10 a - 4 a 3 a —4 a 3 a SUBTRACTION Exercise 3 4. 5. -3 a 15a' -a -2a' 6. 4a6 3a6 7. 3a6 7a6 8. 2 am —6 am SUBTRACTIOn 11 9. 10. 11. 12. 13. 3aH-26 14a + 3c 16a-2 c 12 aft + 16 — 5a — 4 c a+ h 7a— c 3a + 5 c 3 a6 - 10 -2a-5c 14. 15. 16. 17. a^ - 10 ah 2 a^ + 12 a?7i 5a6 16 am 4- mn a^H- 3a6 3a2+ 3 am 4a6 + cd Sam 18. 19. 20. 4 a^c 4- 3 a6 + 10 15 a? 10 a^ + 3 ! a^ 4- 6 a + 7 -2 ah 10a2 + 4a + 4 a^ -4 21. Take a^h + c from 4a + 364-2c. 22. Take 5 a — 6 4- c from 6 a + 3 6 — 4 c. 23. Take 2a4-36— 4c from 4a4-36H-8c. , 24. Take 3 a + 10 6 - 14 c from 4 a 4- 10 6 - 14 c. 25. Take a- + 3 a6 + 12 from 5 a^ - 8 a6 + 16. 26. Take 4a2 4- 3a6 4-2a&2_ 10 from 8a2-16a6-3a62_l. 27. Take 3a2 4-3a + l from 4a3 + 5a2-6a-3. 28. From 3 a^- 2 a^ + e a2 4-2 a-3 take 2a^-a3-4a2- a + 1. 29. From a* - 4 a^ft + 6 a^h' - 4 aW+h"^ take a36+3 a%^+ah\ 30. From -3a2 4-8a + 36 take a2-2a-18. 31. From -16a3-8a2 4-4a-5 take -2 a^ + a'^ -a-\-l. 32. Given a minuend a^4-4a- — 3a4-2 and a subtrahend a^ 4- 3 a^ — 4 a 4- 1, find the difference. 33. Given a subtrahend — 3 ac, a minuend 8 ac, find differ- ence. 12 BUBTRACTION 34. Given a minuend 3 ahc, a difference 4 ahc, find subtra- hend. 35. Given a minuend axy, a difference —axy, find subtra- hend. 36. What must be added to 16 ac to make —Sac? 37. What must be added to 75 m to make 31 m ? 38. What must be added to — 3 a^ to make ? 39. 36 a^ is added to what expression to make 82 a^? 40. What expression added to 4 a -f- 2 c will give 5 a + 8 c^ ? 41 . Given a subtrahend 4a'*4-3a^ — 2a^ + a — 7 and a differ- ence — 3 a^ + 2 a^ — a, find the minuend. 42. Given a minuend 8m^ — 3 mn + 2 n^-f 18 and a differ- ence 2 m^ + 2 mn — n^-\- 16, find the subtrahend. 43. Take the sum of 4 m^ + 2 mn — r? and — 3 m^ — mn -\-2n^ from the sum of 3 m^ -f 12 mn + 10 n^ and — 2 m^ — 11 mn — 11 n^ 44. Subtract x^-Soc^ -\-0(^ -2 — 3 x from a; + a^-3 + 2aj* — X' — a?, and arrange the result in ascending powers of x. 45. 46. 47. 48. 49. 50. ac am X 2 ax 5ahx am he m ex —3 ex 3cdx -2em (a-b)c (a — 1) m (l-e)x (2a + 3c)a; 51. 52. 53. 54 55. 3mn 3aa; + 2 ax-\-by x-\- y 3 ax-\- y -2pn ca;-l ex -\-dy ex — dy x-cy 56. Take 2 6c — 3 ac? from 3 ac + 12 6c?. 57. From ax -{- 3 ey -\- ^ dz take hx — 2dy — az. 58. From 3 ax -\- 2 ay -\- 10 take 2x — y-\-l. USE OF THE PARENTHESIS 13 USE OF THE PARENTHESIS Exercise 4 Simplify: 1. a + (3 a + 2). 2. 4a + (2a-10). 3. 5a + (3a-2) + l. 4. 2a; + (4aj-2/) + (3a;-2)+y. 5. (5m + 7)4-(3m-2). 6. 2c + (3cH-4)-(c + 2). 7. 5m-(m4-l)-(2m-l). 8. 62/-(42/ + 32;)-(22/-42;). 9. 3a + [a + (4aH-3)]. 10. 8a + [a-(2a-l)]. 11. 5 m — J3mH-(2m-l)J. 12. 2a + {-3 + (2a-l)i. 13. lla-[4a-f (lOa-6);. 14. -3a + S2a-(-a + l)S. 15. -2a-[-a-S-aH-lS]. 16. 13a + l-4a-(10a-[a-l])J. 17. a+[a — ;a— (a — 1)J]. 18. a-[-a-5-a-(-a-l);]. 19. 5 a - [2 a - (a + 1) - {3 a - (a + 1) - 1 S - 1]. 20. 6 a - [(3 a + 1) 4- 53 a - 6 - (a + 2) - 3 aj - a]. 21. (5a-l)-[5(3a-l)-10a + 5J-a]-J-(a-2)j. 22. (3 -f a - 1) - [- a + (a - 2 a - 3) - 3 a] - {a - 1 + aj 14 USE OF THE PARENTHESIS 23. (4a2-[3a2-(a4-2)-4]-|a2_^3a-(a-l)|)-a. 24. l-(-l) + (-l)-|l-[l-(l_lTa) + a]-aj. 25. l_J-[_(-l)-l]-li-(-J-[-(-l)]J). 26. Sx-\a-{2a-l3a-{5a-[7a-{Sa-x)J)J)\. 27. -m-[Sn-{-\2p-Sm-(m-n)l-{-7i-\Sm-{m-{-n)\^. 28. (4:a-a + 2)-\a-a-^{a-2)-2\-a-a-{-l. Simplify and find numerical values of the following when a= 5, 6 = 3, c = — 1, d = — 2, and x = 0: 29. a + 6 + c 4- d + a;. 30. 2a-\-c-3b-d. 31. a + 2c-(d + 2)+2(c + l). 32. a + c — d — 36 + a;. 33. 4 6 — d + a6 — aa;. 34. 2a-(c + d)-(a + d). 35. 4a6a;+(a — d) — (6 — c). 36. c +3a; — 2(a + 2a;)+4a. 37. a + 2 6 — [3a + c — S2a — (a; — c)|]. 38. a + 3c — \b + 2x—(a — c)l-]-2d. 39. 3 a — [5 6 — (a6 + d) — a-d] — (a6 + a;). 40. a2-5a;-[3a6 + 462-(a6a; + d)]. 41. aa;-[-64-(a-d)2 + a]-26. 42. (a + c)2+(a-c)2-[a6 + (2 6 + a;)2]. 43. (a-\-c)x — (abx + a)^ — (d + c). 44. (a + a;) 6 - [ V2 a + c - (d + c)]. 45. ic-[c+(a + d)2-26]2+(a-V^6^^)l 46. a62-S3(6 + c)2-[-c+2a(4d+6^]-[6ca;+V3a-c]j. I USE OF THE PARENTHESIS 16 Exercise 5 1. Insert the last two terms of a + b — c in a parenthesis preceded by a plus sign. 2. Insert the last two terms of a — 6 — c in a parenthesis preceded by a minus sign. Insert the last three terms of each of the following expres- sions in a parenthesis preceded by a minus sign : S. a — b — c — d. e. a-\-b + c-{-d. 5. a-^b-c-d. 8. 4a*- a^-f- a^- 3a + l. 9. 6a^-a^-10a*-{-a^-a\ Collect the coefficients of a, of b, and of c, in each of the following : 10. Sa — 2b-\-c — ma — nb — pc. 11. 5a — Smb-\-2nc — 2a — 6nb—3c — ma, 12. 10a — 4^b — 2c — ma — nb-{-pc. 13. —Sa— 4:C — pb — na — mc — b. 14. —c — a + 4:b — Sc-\-da — 10b, 15. —4:a — 3mb — 10c—b — ma — nb-\-pc^da. Collect the coefficients of like terms in each of the following : 16. 4ar^-2ic + 3a^-3a; + 4a^-a^. 17. -Sx^-2x-\-x*-3x^ + 2x-x\ 18. aa^ — ba^—cx — cx^ — dx + a^. 19. a^ + a^ — aa; — ca^ + 3 a^ — 6a;. 20. — aoi^ — cc^ — x — 4: x^ — ax^ — px — ca:^. 21. —px^ — cx-\-3xr — mx — nx^ — mx^ — abx + Sdx^ — cu?. REVIEW Exercise 6 Find the numerical value of : 1. (x-\-2y-{x-\-l)-4: when x = S. 2. (x-2)(x-j-5)-2{x + iy when x = 4:. 3. (a + 6)2 - 2 (a - 1) (6 - 1) - ab- when a = 5 and 6 = 3. 4. Vic^ + m^ — (n — myY when a; = 4, y = 0, m = 3, n = 2. 5. 2 a — [a — (3 a — 2 6)] when a = 3 and 6 = 2. 6. 3a— [4 6 + 2m — 3c + (a — 6) — 2a] when a = 4, 6 = 3, c = — 2, and m = 1. 7. Subtract the sum of a^ + a^ — a and 2o?-\-2a — l from the sum of 3 a^ — a^ — a + 1 and 2 a^ + 4 a — 3. 8. Take m^— 3m^ from the sum. of 2m*— m^ + 2 and m^ — 3 m + 1. 9. From the sum of a^-{-a^ — a and a^ + 4 take the sum of 4a3-2a2 + 17 and a - 3. 10. If ^. = 0^ + 0^4-1, -B = 2a;2-.T + 2, and (7=a^-3a; + 6, find the value of ^ + J5 - C. 11. With values for A, B, and C equal to those in Ex- ample 10, find the value oi A — B-\- C. 12. To what expression must you add 5 a^ to make ? 13. What expression added to a;^ + a; — 1 will make ? 14. — cc^ — a; + 3 is subtracted from 2 a;- — 3 a; + 4, and the remainder is added to — 3a?2 + 2a; — 14. What expression results ? 16 MULTIPLICATION 17 MULTIPLICATION Exercise 7 Multiply : 1. a + 1 by a-f2. 6. a2 + a + 1 by a + L 2. a — 2 by a — 5. 7. a- + a + 1 by a — 1. 3. a + 4bya-3. 8. a'^+Sa^+Sa+l by a+L 4. a- -hi by a2_^2. 9. x'-2x^-{-l by a^ + L 5. a--{-3 by 2a--5. 10. 4 a;' + 4 a.- + 1 by 2a; + l. 11 . a- — 3 a — 2 by a- — a + 1. 12. a''-Sa'--\-3a-l hy cr--2a-\-l, 13. 12?/2-G?/-f-2 by /-32/-f-L 14. a4_4^.3_|_(5^^2_4^^^ j^ ^y a^-Sa^ + Sa-L 15. 5a^-2a2 + 3a-l by 3a2 + a-l. 16.* m^-2m''-h3m2-2m + l by m'^+2m^+Sm^-\-2m-^l. 17. m" - nr -\-Sm — 5 by m^ + m^ -f 3 m + 5. 18. a- + Z>--2a6-46-h4«-f-4 by a-6+2. 19. x^ + x'^ + l-\-x by 1 + a;2 4- a;. 20. l-Yx' + x-'-^Bx by _ 4a^+ 1 -f 2a;2. 21. l-4a'-4.a + Ga'-{-a' by Sa-l+a^-Sa^. 22. .t^-2.t2 + 3 by l-aj2^if. 23. or -\-2ab + h" -{- 7n" by a^ + 2a& + 6^ _ -^2^ 24. a^-a^-^a-1 by 1 -f- a + a^ 4. ^3. 25. 5x'-2x' + x'-3 by - 3x' -^2x' -2 +x\ 26. a^ H- 2 a5 -f ?>^ by ct" - 3 a-& + 3 ab'- - h\ 27. a^ - 4 o&-^ + ^' + T) a7>2 _ 4 a-^& by 52 ^ a- - 2 a6. R. & S. EX. IN ALG. — 2 18 DIVISION 28. 3a^b-2 a^V + 4 a6« by 2 a^h ^V- ah\ 29. 5 a^m + 4 aW — 3 «%^ — am** by 2 a^m — 3 am^. 30. (a + 1) (a + 2) (a + 3). ;a + 2)(a-2)(aH-l). a + 1) (a - l)(a + 3)(a - 3). > + 2) (» + 2) (« - 2) (a; - 2). V + m-\-l) {m^ — m -f 1) (m} — m ;3 a,.2 _ 5 ^ _l_ 3) (^ _ 4) (^ _ ^ ^ 2), 31. 32. 33. 34. 35. 36. -1). [a -\-h)-\-2 by (a + &) + 3. 38. (a + 2) + 3 a; by (a + 2) + 4 a;. 39. (a + c) — 4 by (a + c) + 6. 40. (a + 6) + (c + d) by (a + 6) +2(c + d). Divide : 1. a^ + 4a by a. 2. 3a3 + 6a2 by 3a2. 3. a^ — a^-\-or by a^. 4. a"* — a^ + a- by —a^ DIVISION Exercise 8 5. Sa + lOa^ + loa'^ by 5a. 6. 12m=^-9m2+3m by 3 m. 7. — ??i"^ 4- ?yi- + 4 m by —m. 8. 15a252_75a6 by -5 aft. 9. 27a^6^ + 36a26^-18a&^ by -9a&^ 10. a^.^ 4a + 3 by a 4- 1. 11. l + 8a + 15a2 by l+3a. 12. a34-3a2 + 3a + l by a + 1. DIVISION 19 13. Sa^-{-12a^-\-6a-{-l by 2a + l. 14. 16-32a + 24:a^-Sa^ + a' by 2-a. 15. a^-4a3 + 6a2-4a + l by a'-2aH-l. 16. m^ -\- 5 m^n -{- 5 mn^ -i- n^ by m- + 4m7i + 7t^. 17. 4m^-9m2 + 6m-l by 2m^-[-3m-l. 18. a^-10a* + 40a3-80a2 + 80a-32 by a2-4a + 4. 19. m*-3m3-36m2-71m-21 by m^-Sm-S. 20. 4a^-15a-^c + 26aV-23ac3 + 8c* by 4a2-7ac + 8c2. 21. m^-6m^ + 5m2-l by 7/1^ + 2 7/i2_^,t_l. 22. a^ + 12a2-48 + 52a-17a3 by a-2 + a2. 23. m'* 4- 4 mV + 16 71* by m^ + 2 mn -f 4 ?r. 24. 18c* + 82c2h-40-67c-45c3 by 5-4:C + Sc\ 25. 4a;2-(-13a;-6a:3 + 6 + a^-2a;* by 1 -{-x' + 3x + Sx^. 26. 25 m - lOm^ + 15 + 14 m*- 41 m^ by -5m — S-{-7m^' 27. -14c*d + 12c^ + 10c3cZ2_c2d3_g^^^4_^4^^5 ^y 2cZ3-3cd2-4c2d + 6c^ 28. m^ — n^—p^ — 2pn by m — n—p. 29. c^ + d^ + 77i^— 3 cdm by c + cZ 4- m. 30. a'^4-6^ + c3-3a6cby a^ + fts^c^-ac-ftc- a6. 31. x'-y^hj x-y. 38. 64 + 27 a*^ by 44- 3 a. 32. o^-fhj x-y. 39. 16-81 a* by 2 + 3 a. 33. a;*-2/*by a;-2/. 40. 125 0^-8 by 5 c- 2. 34. x*-y^hj x + y. 41. 216 771^-27 by 6 m-3. 35. «3-27bya;-3. 42. 81 a;*- 16/ by 3a; + 2 i/. 36. a;*-16by a; + 2. 43. 9m*-49 c« by 3 7n,2^7 c*. 37. 32-m^by2-m. 44. 27 d^ 64 6^ by 3 c^H 4 6'. 20 MULTIPLICATION BY INSPECTION MULTIPLICATION BY INSPECTION Exercise 9 The square of the sum of two quantities. Expand by inspection : 1. (a + 6)2. 5. (a + 3)2. 9. (3 a + 0)1 2. {a + cy. 6. (a + 5)2. lo. (2a + 3a.f. 3. (a + m)l 7. (a + 10)1 11. (J ax-\-^y. 4. {a + 2y. 8. {2a^hy, 12. {^a? + dhy. The square of the difference of two quantities. Expand by inspection : 13. {a -by. 17. (a-2cy. 21. {2a-^cdy. 14. (a -my, 18. (3 a -2)2. 22. (3a2_2a5)2. 15. (a -4)2. 19. {db — cy, 23. {4.ax-xyy. 16. (a -6)2. 20. {a?-ahy. 24. (9a2-10c2)2, The product of the sum and difference of two quantities. Multiply by inspection : 25. (a + 6)(a-6). 30. (2 a6 + 1)(2 a& - 1). 26. (rt + c)(a-c). 31. (4a+3)(4a-3). 27. (a + 2)(a-2). 32. (pa^ -2c)(p 0^ + 2 c). 28. (a-4)(a + 4). 33. (S> a" -7 ah)(Qa? + 1 ah). 29. (a2-3)(a2 + 3). 34. (5a;^/-3a^)(5a;^/+3a;;^). MULTIPLICATION BY INSPECTION 21 Perform the indicated multiplications: 35. {a-2c)K 41. (a6c-2)2. 36. (a-{-Sxy. 42. {arm -\- mn){am — mvi). 37. (a2-2)(a2 + 2). 43. (4 ac + 7)(4ac-7). 38. (a^-l)(a^ + l). 44. (6m2-3)l 39. (a3 + 3)2. 45. (8m-h5)(8m-5). 40. (a6 + 5c)2. 46. (3 (r' + 5)(3 c*- 5). The product of the sum and difference of two quantities obtained by grouping terms. Multiply by inspection : 47. [(a + ?>)+c][(a+6)-c]. 55. (a'+a-irVjipi^-^-a-l), 48. [(a4-«)+3][(a+a;)-3]. 56. {a-x+y){a-x-y). 49. [(a-2)+c][(a-2)-c]. 57. (a-x-^y){a-irx+y). 50. [(a2+l)+a][(a2+l)-a]. 58. (c-d4-3)(c+d+3). 51. [cH-(a+6)][c— (a+6)]. 59. (a+m— n)(a— m+zi). 52. [m4-(w-p)][m-(n-i))]. 60. (c+cZ-3)(c-d+3). . 53. (a + 6 + c)(a + &-c). 61. (x2-l+a;)(ar^-l-ic). 54. (a+a;+2/)(a+a;— 2/). 62. (o^+a;— l)(a;2_^_j_j^)_ 63. [(a + &) + (c + ^)][(a + &)-(c + cr)]. 64. [(m + w) — (a;-2/)][(m + n) + (a;-y)]. 65. (a — m + n — l)(aH-m+n4-l). 66. [m«-3m2-m-3][m3-|-3m2 + m-3]. 22 MULTIPLICATION BY INSPECTION The square of any polynomial. Expand : 67. (a + 5 + c)2. 71. (a^ + a - 2)1 68. (a + 6-2c)2. 72. (2x^ -S xy - 5f)K 69. (a-\-b-c- df. 73. (a^ + 2 a^ - 2 a - 3)1 70. (a + 26 -3c + («)'. 74. (2a^-ar^2^+3a;2/'-22/3>)2^ The product of the forms {x ±a){x ±b). 75. (a; + 2)(a; + 3). 82. {x-^){x + 12). 76. (a; + 3)(a; + 5). ' 83. (a^- 3)(a^ + 7). 77. (a? + 10)(a; + 7). 84. (a:^ _|_ 4^)(^^ _ i3>)_ 78. (a; + 3)(a; - 2). 85. (a^ + 2)(a.'3 + 19). 79. (a; + 4)(a;-5). 86. (y?f ^-l){x'y'' -2). 80. (a;-4)(a; + l). 87. (aa; + 13) (aa; - 12). 81. (a7 + 3)(a;-16). 88. {a'cx-ll){a^cx -\-Z). The product of the forms {ax ± b)(cx ± d). 89. (2 a; + 1)(3 a; + 5). 95. (a' - 3 a)(4: a^ -\- 2 a). 90. (3 a; + 2)(4 x + 3). 96. (4 ac + 7 m)(3ac- 67/1). 91. (3a-7)(2a + 3). 97. (llx'-3y%5x' -\-f-). 92. (3m-^Sx){Sm-llx). 98. (mn - 13 1/) (5 mw + y). 93. (4a + 3c)(3a + 2c). 99. (llm^-37i){3m^-\-nn). 94. (2c2-7)(3c2-ll). 100. (6cd-3dm)(4:cd-\-Sclm), DIVISION BY INSPECTION 23 DIVISION BY INSPECTION Exercise 10 The difference of two squares. Divide by inspection : 1. ^2- 62^ a- 6. 6. 25m2-81-^5m^-9. 2. a^-9-^a-\-3, 7. 81 ?>i^ - 49 -- 9 m^ - 7. 3. ci2_16--a-4. 8. 64 a^ - 36 ^ 8 « + 6. 4. 4a2_l^2a+l. 9. 169 a" -9 -r- 13 a + 3. 5. 16a2-9-j-4a-3. 10. 4m^ - 225 -^ 2m2- 15. The difference of two cubes. Divide by inspection : 11. m^-ji^-j-m-n. 17. 8 a« - 1 ^ 2 a - 1. 12. a^-b^-i-a-b. 18. 125 m^ - 27 -- 5 wi - 3. 13. m^-l-i-m-l. 19. 1 - 512 m«-^ 1 - 8 m^. 14. C3-8--C-2. 20. 343(^-d^^7c-d^ 15. 2T-x^-^3-x. 21. 125-216?7i»-r-5-6m3. 16. l-64a3--l-4a. 22. 1000 - mht^ Sr 10 - mil. The sum of two cubes. Divide by inspection : 23. m^ -\- 71^ -i-m + n, 26. 64a3 + 27 ^4 m + 3. 24. 8 + C3-2 + C. 27. 125a3 + 8--5a + 2. 25. 27m3 + lH-3m4-l. 28. a^m^ + 27 ^ am + 3. 24 DIVISION BY INSPECTION 29. a«m« + 64 -r- aW + 4. 31. 216 a^ + 512-f- 6 a + 8. 30. 8a^-f343^2tt + 7. 32. 1000 a^ + 729 ^10 a + 9. The sum or difference of like powers. Divide by inspection : 33. a'^-b^-ha-b. 39. a^ + 32 -j- a + 2. 34. a^-b^^a-b. 40. 16a^-l-f-2a + l. 35. a^-b^-^a + b. 41. 32 a^ + 1-1-2 a + 1. 36. a^-\-b'-i-a-[-b. 42. 81 - 16 a* -J- 3 - 2 a. 37. a^ — ¥-^a — b. 43. 64 — m« -s- 2 + m. 38. a^-16H-a-2. 44. 32 + 243 a^^ 2 + 3 a. Give the binomial divisors possible for each of the following : 45. a^-8. 48. a* -81. 51. 9a*-16. 54. a«-9. 46. a* -16. 49. a^-64. 52. 81 - a\ 55. a^-\-b^. 47. a^ + 32. 50. a^-b\ 53. 16 - a^ 56. a^^ _ 512 Give the quotients of the following : 57. a2-16--a + 4. 62. 125 a^ - 8 -^ 5 a- 2. 58. a^-16--a-2. 63. 100 c^ - a^ -f- 10 c^ + a^ 59. 4a*-25--2a2+5. 64. 36 m*- 1 ^ 6 m^-f 1. 60. 81 a* - 36 c^ -f- 9 a^- 6 c. 65. 64a«- 27c^2^4a2-3c^ 61. lOOm^-l-^lOm^-l. 66. 1 - 81 ««-^^ 1 + 3 al 67. 100(a4-l)'-9^10(a + l) + 3. 68. 27(a + l)^-8c-^--3(a + l)-2c. PARENTHESIS WITH MULTIPLICATION 25 USE OF THE PARENTHESIS WITH MULTIPLICATIOK Exercise 11 Simplify : 1. a4-(a + l). 9. (a + 4)(a-2). 2. a+(2a-3). 10. 2a-\-S(a-3). 3. a + 2(a + l). 11. {a-{-l)(a + 2)-a\ 4. a + 2(a-4). 12. (a + 2)^ + (a + 1)2. 5. a2+(a + l)'. 13. (a + 4)^ - (a + 2)2. 6. a + 2(a-l). 14. 7 a^ - 2 (a^ + 1). 7. (a+2)(a-l). 15. 2(a4- 1)'- a(a + l). 8. 5a + S(a + 2). 16. 4(a - l)2-3(a + 1)1 17. 4a + (a 4- 1) (a -1) -(«-!)'« 18. 2(a + l)(a4-2)-(a + l)(a-2). 19. (a + l)2-(a + l)(a-l)-2a. 20., 3 a^ + (a + 3) (a - 1) - (a - 3) (a + 1) - 2 (a^ - 2 a). 21. 2 (a + 1)' - 2 (a + 1) (a - 1) +3 (a - 2)\ 22. (a + 3)2-2(a + l)2 + 3(a + 2)2. 23. (m + n)^ — m{m-\-nf — n (in + n)^. 24. m (m + n)2 -|- n (m — ?i)2 — (m + n)^ 25. (a — m)(a — w) —(a — m)(a — p) — (m — a) (n — i?). 26. (m -{- n 4- p)^ — m (n + j9 — m) — n {m + p — n) . 27. (3m4-l)(3m-l) + [mn - Jl-m (2w-9m)J]. 28. 3 a - [2 a + 3 (a - 1) - 2 (3 - 2 a)] - 4. 29. 2[3a-4(2a-l) -3(-2a-^r:^)]. 30. 116-5[3-2 J8 + 3(4-2[8-3T^])|]. 26 SIMPLE EQUATIONS SIMPLE EQUATIONS Exercise 12 Solve the following equations : 1. 3x + 4: = 2x + 5. 6. 2(x-\-S) = A + (x-2). 2. 5aj + 9 = 2a;+.15. 7. 5 (x-2) = 3 (a;+l)-l;i Z. Sx-4: = x + 12. 8. 7aj-(;^j-3)-12 = 2a-. 4. 4a.' + 3 = a; + 6. 9. 3 (x + 2) +x^ = 5 -\- x\ 5. 5a; + 7 = 2 0^4-9. 10. (a^+l) (a:+2) =a;(a;+l). 11. 4 + 5 (a; + 2) - 9 a; = (a; 4- 2)2 - x\ 12. (x + 2)(x-5) = (x + 4) (x - 1). 13. (a;-l)(a;H-3)-2(a;4-l)(aJ-5)+a;2^0^ 14. 2(a;2 + 2a; + l) - (a; + 2) =2a;2 + 6. 15. (x + 4:y + (x + iy= (a; + 3)2+2a;(a;+l)-a^. 16. 3 (a; 4- 5) (a; + 2) - (« + 3) (a; - 1) = 2 ar^ - (a; + 7). 17. (4a;-l)(a; + 3)-4a;2_(_i0^_^3)_^(3^Q ^ 18. 2[a; + a^(ic-3)H-l]=(2a; + 5)(a;-l). 19. 5S2(a; + l) -(a; + 3)S =3[a; + 2Sa;-5(3-a;)S]. 20. 2 [3 a^ 4- (aJ - 2) (a; - 1)] = 3 [2 a^ + (a; - 3)] + 2 a^. 21. 3[5a;-(a;4-3 4-2a;-l)] = 3a;-4 53a; + 2(a;-l4-3a;)J. 22. [(a;-2)(a;4-l) + (a; + 3)(x4-2)] = [(a^4-3)(aj-5) ^(x-5)(x + l)l 23 . (a; 4- 2) (2 aj 4- 1) (3 a; 4- 3) = (6 a; - 3) (a; 4- 1) (a? + 3). 24. aa; + a = 4a. 27. 2cx + d = 4:G^-\-d. 25. 2ax-{-c = 5c. 28. ax — (a-\-b) = 3a+b. 26. 4aa; — 5c = 5a — 5c. 29. 2(a — a;)=8a. PROBLEMS IN SIMPLE EQUATIONS 27 30. 3(x-{-a)-\-2{x — a) = 6(a — x). 31. (a + b)x-^(a — b)x = a^b, 32. 5 a -\- (a -^ bx) c = ac — bcx. 33. 10(a + b) -\-3x=a-\-b — 5x. 34. S(a + b)x — 2(a — b)x = a-\-5b. 35. (x — m)(x — n) = {x — m — iif. PROBLEMS IN SIMPLE EQUATIONS Exercise 13 1. What number is that which, when doubled, equals 24 ? 2. What is the number that, increased by 12, equals 27 ? 3. If a certain number is increased by 12, twice the sum will be 28. What is the number? 4. Four times a certain number when diminished by 6 is equal to 12 more than the number. What is the number ? 5. There are two numbers whose sum is 77, and the greater is 13 more than the smaller. Find them. 6. A man is 13 years older than his brother, and the sum of their ages is 49 years. Find the age of each. 7. A father is 4 times as old as his son, and the sum of their ages is 55 years. Find the age of each. 8. The sum of the ages of three brothers is 85 years. The oldest is twice the age of the youngest and 5 years older than the second. Find the age of each. 9. A child is 3 years older than his brother, and 5 times his age is 3 years more than 6 times his brother's age. Find the age of each. 28 PROBLEMS IN SIMPLE EQUATIONS 10. Five years ago a man was 4 times as old as his son, but now he is only 3 times as old. Find the present age of each. 11. A man bought the same number each of 2-cent, 5-cent, and 6-cent stamps, paying ^ 0.91 for the lot. How many of each kind did he buy ? 12. Find three consecutive numbers whose sum is 39. 13. Find three consecutive odd numbers whose sum is 33. 14. Find two consecutive even numbers, the difference of whose squares is 52. 15. A man bought a number of horses at $ 150 each, twice as many cows at ^40 each, and 3 times as many sheep at $ 5 each. The lot cost $ 1225. How many of each kind did he buy ? 16. How can you pay a bill of $ 80 so as to use the same number each of 1-dollar, 5-dollar, and 10-dollar bills ? 17. A man asked a farmer how many cows he had, and was answered, '' If you gave me 18 more, I should then have twice as many as I now have." How many had he ? 18. A man sold 15 hens, receiving 80 cents each for a part and 50 cents each for the remainder. He got ^ 9.60 for all. How many were sold at each price ? 19. Three dollars in nickels and dimes were distributed among 42 boys, and each boy received one coin. How many boys received dimes ? 20. Into what two amounts must $ 1700 be divided so that the income of one part at 5 per cent interest shall be double the income of the other part at 6 per cent interest ? REVIEW £zercise 14 1. If a = 3, 6 = 1, c = 0, and cl = l, find the value of a — (a — b) + \a — {b + c)l — [a — (b — c — d)]. 2. From what expression must you subtract the sum of 5 a^ 4- 8, 3 a 4- 2 a^, and a^ -\-a—l, to produce the expression 4a2-8a + 3? 3. If a = 7n-\-n — 2p, b = m — 2n-{-p, and c = ?i+p — 2m, show that a -j- 6 4- c = 0. 4. What must be added to a^ + a^ — 2 a 4- 3 that the sum may be — a^ — a^ 4- 2 a — 3. 5. To what expression must x* — 3x^ + 2a^ — x-\-5 be added to produce a^ — x — 1? 6. What is the numerical value of the remainder when 3a4-2c — d is subtracted from 4a4-3c — 2d if a-\-c = d and d = 7? 7. If A = a^-l-^4:0^, B = -x-2x'-\-l, and C=2a^-i- 2 0)2 + a; + 1, find the value of - A-[B- (2 A- C)-\- C^ 8. Simplify 4a- [- 6c- (- 54-26-3 (^) -4 a] -5- (4c -3 cQ. 9. Simplify i-[-i+!-i-(-i+?-i+(-i)s-i)n- 10. What is the coefficient of x in the reduced form of the expression (x — 4a) — [2a — Six — 2 (x — a)j]? 29 30 BEVIEW 11. Multiply m^ — 2m» + 2m- — 2m + l by m* + 2m^ + 3 m^ -{-2m-\- 1. 12. Multiply a*b - a^b' -\- a^b^ - ab^ by a^b - d'b^ -\- ab^ 13. Multiply ^a^ — I tt2 + a — 1 by i a — 1. 14. Multiply 0.1 aj2 + . 04 0^4-0.5 by 0.1 x-^ + 4 ic + .05. 15. Divide Gm^ + ^/i^ — 29m2 + 27m — 9 by 3m^ + 5wr — 7 m + 3. 16. Divide 1.2 aj^ - 2.9 a^ + -9 a;^ + a; by .3 a; -.5. 17. Multiply by inspection (a -{-b — 2)((i—b — 2). 18. Multiply by inspection (a -\- b — c) (a — b -{• c). 19. Expand by inspection (a — 2b-\-Sc — d)\ 20. Divide 1 by 1 — 3 m to 5 terms. 21. Divide m'^ by m + 2 to 4 terms. 22. Simplify (5 a + 1) (a - 3) - (2 a - 3/ _ (a - 5) (a + 3). 23. Simplify (2a-l){a-{-4:)-2a'-\3a-{-(2 a-l){a-6)l. 24. Simplify 5 a + (4 a - 1) + « + 3 (« + 1) - (a + 3) (a + 1). 25. Simplify 4 a^ - 3 a [a^ + a^ - (a - 2)] - 3 (a + 1) (a - 7). 26. Find the value of (a + bf — (a + c)^— 2 (a + 6 + c) when a = l, b = 2, and c = 0. 27. Find value of -^ + V6^-4ac ^ ^j^^^ ^^5^ 5^_11^ and c — Z. 28. Find value of -?>-V&^-4ac ^ ^^^^^^ ^^^^ & = -ll, and c = — 3. 29. [(a; + a)2 4- 5(a; + a) + 4] -- [(a? + «) + !] = ? 30. [5(a; + m)4-3][5(a;4-m)-3] = ? 31. Solve 2a — 3a;(a + c) = 5a + 3c. FACTORING 31 32. Solve x'-(x-\- af = (a + If. 33. Solve a'-\-{x-l){x-2) = x' + (a-l){a + l). 34. Solve 4(a; + 4)(a;-3)-2(a^-2) = 3(a; + l)(x-4)-cc2. FACTORING Ezercise 15 Factor : 1. a^^a^ + a. 10. Ga-^-Qa^ + Sa. 2. m^ — m^H-m. 11. 5 m — 10 7)i^ + 15 m\ 3. 2m + 4m2 + 6m». 12. 12 m' - 18 m^ + 24 m«. 4. 5c2+10cH-15. 13. 5ac— 10 6c + 5 cd. 5. a24-4a^ + 6a*. 14. 4 a^c _ 10 ftc^ + 6 ac. 6. 3a^ + 9aj^-6a^. 15. 6 a^y -\- S xy^ - 9 x^. 7. 10 a.-3 - 12 ar^ + 13 £c. 16. m^ -S m' + 4.m^-m^ 8. 8a:^-12x»-16ar2. 17. a^c - aV + aV + ac^ 9. 4a3-f 8a2 + 12a. 18. S a'-\-^a^-2 a^ -{-6 a^ 19. a'b-a%^-{-a^b^-ab\ 20. 4a*6-12a^62-16a^63 + 8a*6^ 21 . 15 ay + 150 ay - 225 a/ + 15 a/. 22 . 48 7n^n^ - 144 mhi^ - 192 m«ri^ + 240 m'^'n^K Exercise 16 Factor : 1. a2 + 4a + 4. 4. a^-20a; + 100. 2. a2 + 6a + 9. 5. a2-18a + 81. 3. a2-8a4-16. 6. 4m2H-4m + l. 32 FACTORING 7. 0,2 _^ 22 a + 121. 18. 25 a' - SO a -}- 9. 8. 16c2 + 8c + l. 19. 9a2-30a + 25. 9. a2-36a + 324. 20. 49c2-84c + 36. 10. 36a2-12a + l. 21. 16 a^b^ + S abc -^ c". 11. 9-6a + a2. 22. a^ + lSa^ + Sla. 12. m2 + 42m + 441. 23. 36 a^ + 60 a'c -\- 25 a^c^. 13. a-^>--14a6 + 49. 24. 144 m^ - 240 m/i + 100 w^. 14. ify + 32a'2/ + 256. 25. 121 x^ - 374 a.-^ + 289. 15. cv'cH^- 10 acd-\- 25. 26. 625 m^ - 50 ?7i + 1. 16. 64-16m?z + mV. 27. (a + 6)2 + 2(a + 5) +1. 17. 4a2+12aH-9. 28. (a + by -^6(a + b) + 9. 29. (a-c)2-6(a-c)H-9. 30. 25(a-m)2-70(a-m)+49. Exercise 17 Factor : 1. a'-b\ 11. 64a;2-25. 21. 81a^-49a. 2. a2-4. 12. a*-l. 22. 81mV-16. 3. a2-4m2. 13. a^-Slc^. 23. 324- 256 a^/. 4. c2-9fZ2. 14. aV-25. 24. 289 - 16 m^. 5. 0^2-16. 15. 9a*-4a«. 25. (a + 6)^-1. 6. m2-49. 16. 6a^-24a. 26. (m-ri)2-4. 7. 9 0^-16. 17. 3 ar^- 75 X. 27. 7ri'-(n-^py. 8. 25 a^b^ -9. 18. a^6^-81. 28. 9a''-(b-cy. 9. 36c2-25. 19. 121 a^- 49. 29. 4(a + &)2-c2. 10. 36c2d2_9^ 20. 64a*-a8. 30. 16(x-yy-9. FACTORING 33 31. 4a2_9(a + l)2. 34. 36 (a + &)' - 49 (m - w)^. 32. 9 a^- 16 (a + 2)2. 35. {a? - Wf - 4. {o? -{- Wf 33. 2^{a-hf-{c-\-df. 36. 100 - (a -f- 6 + c)^. 37. 81(a + 6)2-4(a + 6 + l)2. 38. 9(a2 + & + c)2-16(a2_&_c)2. Exercise 18 Factor : 1. a^ + 2ah-\-h'^-c\ 11. (? -^ cd-\-^dr -lQ>m\ 2. m2-2mn + n2-p2^ 12. 4«6-4 a^-f- 1 - 61 3. x'^ — h'^-[-y'^ — 2xy. 13. in^ — A mn - 9 7n-n^ + 4: n\ 4. m2 + ?i2-j92^2mn. 14. 9 a^-2522 + 16/ + 24 a-?/. 5. m2+n2-^2_2y^n. 15. 4a2 + 12a6-9c2 + 9&l 6. 2m + n2-m2-l. 16. 20 mn -^ p^ - 4: m^ - 25 n\ 7. l_a^-2a;y-2/^. 17. 4a2 + a*- 4a3-l. 8. ar^_4a2-4a-l. 18. 5 ar'-S-Sa^-lOa^. 9. 2mn + mV + l— p2. 19. 8ac — 4 a2_4c2 + 4. 10. ci--c2-l-2c. 20. m^ + 16n^-16-\-Smn. 21. a--^2ab + b- — 7nr — 2 mn — n\ 22. 4a2-4a + l-9a.'2-|-6a;2/-/. 23. 9a'-30a + 25-4.b'-4:b-l. 24. a2-c2 + 62_^2_2a&_2cd 25. a%^ ^ 10 a'mhj - n^ - 1 _ 2 n + 25 /. 26. 711^ — n'^ — x^-\-if — 2 (my — wic). 27. 25 a^ + 1 - 1 6 a^ _ 9 c^ - 10 a2 _ 24 a^c. R. & 8. EX. IN ALG, — 3 34 FACTORING 28. 5a2 + 562_5m2-10(a6 + m7i)-5w«. 29. -12a6 + 2 + 24a25_i862_^18a262_8a*. 30. 3a2 + 1262_l2a4_i47 52_34^2^_-|_2«5. Factor : 1. m^ + m^n^ + n*. 2. x^-lx^y'^-\-y\ 3. iB*-5a^3/2^4^^ 4. m*-23m2 + l. 5. a^-79a2 + l. 6. m*-171m2 + l. Exercise 19 7. 25a^ + 66a262 + 496^ 8. 49 X*- 11 a;22^2_^ 25 2/^ 9. 16a;*-73a^ + 36. 10. 49a^-74a262^25 6*. 11. 289m^-42mV + 169w^ 12. 16a*-145a262 + 9 6*. Factor : 1. a2 + 3a + 2. 2. a2-a-12. 3. a2-9a + 20. 4. ar' + 5a;-24. 5. a2 + 18a + 17. 6. c2-llc + 24. 7. m2-19m + 88. 8. c2-9c-22. 9. a;2^5a._14. 10. a2-3a-28. 11. iB2^9a.^i4^ Exercise 20 12. 2/'-ll2/ + 28. 13. ar^-9a; + 14/ 14. c2 + 42c--43. 15. m2-4m-165. 16. 2/' + 12 2/ -108. 17. aV-21aa;-46. 18. a262 + 13a6+40. 19. aW + 21 am -130. 20. c2d2 + 9cd-52. 21. mV-2??i2n-35. 22. ic2«2_20fl;;2-69. FACTORING 36 23. x^f-xy-12. 34. m* — m*-156m^ 24. a;^-13ic2 + 36. 36. a^+ (a + &)a; + a6. 25. ic^ — 9 a^ — 22 ic. 36. a;^ + (m + n) a; + mw. 26. a;* — Sar' — 9. 37. a^ -\- {c + d) a -{- cd. 27. a^ — 7a^ — 78 a. 38. x^ — {m-\-n)x-{-mn. 28. a262_6a6-187. 39. a;^^ (a4- 26)a; + 2a6. 29. 16-6a-a2. 40. a^+ (3a + 2 6)a;+.6a6. 30. 18-19c+c2. 41. iB2_(a-6)a;-a6. 31. 147 - 46 a--^ - a;«. 42. x^-ax-hx + ah. 32. 90m24-13m^-m«. 43. a^- (3m-2)a- 6m. 33. a:3_^i0a:2_963.^ 44^ a^-\-{m-2m7?)ay-2m?ii?y\ Ibcercise 21 Factor : 1. 2a2 + 5a + 3. 14. 8a2-30a-8. 2. 6ar'-a;-2. 15. 24m2-14m-49. 3. 2ar^-3a;-9. 16. 2 a;^ -f 7 a; - 15. 4. 2a2 + 7« + 3. 17. 18a2-f-9a-2. 5. 8a^+^a;-3. 18. 40 ar^ - 61 a; + 7. 6. 6m2+^m-5. 19. 8m2 + 2m-3. 7. 15ar^ + lla; + 2. 20. ^b a" - IS a - 12, 8. 7ar^-41a;-6. 21. 6a2 + 25a-9. 9. 6a2-29a + 28. 22. 8m2 + 5m-3. 10. 3a2-19a + 6. 23. 4.2 x" - 11 x - 20. 11. 12c2 + 17c-5. 24. 16m2-67n-27. 12. 6/-y-12. 25. 12y^-y-20. 13. 3m2-llm + 6. 26. 2x'-4.x-12^, 36 FACTORING 27. 12 m^ - 7 m^n- 12 m?il 36. 20 a^^^ - 9 a^ft^ - 20 a&. 28. 6m3 + 29m2-22m. 37. 16 0^^2 + 2 ccZ- 3. 29. 8x^-26^^2 + 18. 38. 75 a - 210 aa; + 147 ax^ 30. aW-9aW + 20a2m. 39. 48 a;^ - 176 x* + 65 aj^. 31. 26a34-197a2 + l5a. 40. 55x-«-x^-2x3 32. 52a2-153a-52. 41. 2(a + l)2 + 3(a4-l) + 1. 33. 3m2-30m + 63. 42. 3(a + 1)^- 8(a + 1) + 4. 34. 12x^-25x2 + 12. 43. 2(a + l)2 + 5(a + 1) + 2. 35. x«-x*-42x3. 44. 2(a-2)2-5(a-2)-3. 45. 3 (m - 1)2 - 11 (m - 1) ri + 6 nl 46. 10 (a + 6)2 - 11 (a2_ 62) + 3 (a -6)2. Exercise 22 Factor : 1. m^-n\ 8. a365-8. 15. 343 «%« - 729 7i«. 2. m3-27. 9. 27- 8 c^c^^^ 16. {m^nf + 3?. 3. 8a3 + l. 10. 7MV-343. 17. (c + d)»-8. 4. 27-8c3. 11. 64a3 + 125. 18. (a + 1)^ + 64. 5. 27a3 + 8. 12. 8a«-27. 19. 27-8(a + 2)3. 6. 64- 125 c^. 13. 64a» + c^ 20. 64 (a + 6)^ - 27 a^ 7. 125a3+2763. 14. 125mi2_^i5^ gl. (a + 1)^ - 8 (a + 2)^. 22. a^-h\ 26. a}''-2^. 30. (a -6)^-1. 23. a^-16. 27. 4m^-81. 31. (a-6)«-8. 24. 81 -m^ 28. a^^'-w}''. 32. (a + 6)^ -256. 25. a«-64. 29. m^^-'n}^ 33. (2a+l)^-16(2a-l)^ FACTORING B7 34. m^ + 8. 38. x^'^-^y^^ 42. x^^ + 1. 35. m^ + 1. 39. x^ — y^ 43. m« + 27. 36. a^ — l. 40. a;^ + 2/^ 44. 64a« + l. 37. 3^ -{-32, 41. i»8-^. 45. a}^ + 7n^. Exercise 23 Factor : 1. m^ + mn + mp -{- n2). 13. m^ + 5m2 + 2m + 10. 2. ab-\-a-\-7b-\-T. 14. m^w —p^mn -f- mic — p^a;. 3. 2c7n-3dm-\-2c-Sd. 15. a^- 1 + 2(a2- 1). 4. ay-ab-bx-\-xy, 16. a^ (a^ - 9) - a (a + S)^. 5. a:3_^^_^a.^l^ 17. 5(a^ + 8)-15(ic + 2). 6. xy-2y-x^-{-2x. 18. a;^4-2a^-8a;- 16. 7. a^-a^ + a-l. 19. 2a2(a + 3) -Sa^-Sa + S. 8. m^-n^-m-n. 20. c^-\-4:C^-S. 9. a^-a^-a + l. 21. m^-lOm-SO. 10. 6a3 + 4:a2_9a-6. 22. 4a3-39a + 45. 11. m^ + m^-m-l. 23. a3 + 9a2 + ll a_21. 12. 15 ax-2llay+9bx-12 by. 24. a'^ + 3a2+ 3a + 2. 25 . am -{- an -\- ap -{- bm -\-bn-]- bp. 26. m^ {n — x) -{- m{n — X) —2 (n — x), 27. m^ + ?/^ + m — 2m2/ — 2/-^6. 28. (a-l)(a + l) + (a;-l)(a-l). 29. (a + l)(aj + 2)-(a + l)(y + 2). 30. a^-l-xia-l). 31. m^ + l — ^>(m + l). 32. (m + l)(m2-4)-(m + l)(m + 2)-m-2. REVIEW Exercise 24 Factor : 1. 6a2-fl9a + 10. 18. 24: a^b^ - 36 b* - SO ab\ 2. 2x'-6xy-U0y\ 19. 7a;^-7a;. 3. a*-\-a. 20. m^~m'^-2m^ 4. c*-^(^d^ + d', 21. m* + n*-23mV. 5. m^ — m^ — SOm. 22. 42/ + a;2 — 1 — 4^2 6. c* + cc?8. 23. (2m-5n)2-(m-27i)2. 7. a^ + 2xy-ix^-y\ 24. 4a%2_4ci2^4^8^3^3_3^^6^ 8. a;4_iB3a + iK2;3_^2^^ 25. 25a^b^c'-9, 9. a^-oc^y + xy^-y\ 26. a^-Sa-a^ + S. 10. 1 — m^ — 2 mTi — n^. 27. a;^ — /. 11. c^ + (^4_-|^8g2^2^ 28. m^-rn?n-\-mn^-n\ 12. m2wy_^2p_^?p_^j 29. 81m«-16m7i^ 13. 6(?-c{d-V)-{d-Vf, 30. 72aH5a2_i2a. 14. a2-c2-4c-4. 31. l + aa;-(c2 4-ac)aj2. 15. d2 + 3cf-d^-3ci. 32. 54-16mW 16. 8a^4-27a;2^ 33. 4.^f-(^^y^-zy. 17. JK« + 2/3, 34. 49a^ + 34a^2^H-25y. 35. (a; — m) (2/ — n) — (a; — n) (y — m). 36. 15m'-14m^-8m3. 38 REVIEW 39 37. (m-n)(2a2-2a6) + (n-m)(2a6-262). 38. (a-l)(a-2)(a-3)-(a-l) + (a-l)(ci-2). 39. (2c2 + 3d2)a + (2a2 + 3c2)d. 40. d^ + d^-d-^l, 62. 2m3n-16ni^ 41. x^-64:. 63. 64a;^-a;. 42. 1000 + 27 c«. 64. (a^+a -l)2-(a3-a-l)l 43. 5a3-20a2-300a. 65. a;^-27ar^ + l. 44. mn— pr+j97i — mr. 66. Slx'^—y^z^^. 45. c2-2cd + d2-l. 67. 5cd-12d' + 2c'. 46. 4-9(a;-32/)'. 68. 72 ic^ _|. gg ^ _ 40 ^.^ 47. a'i»^-a^-a^-2ax. 69. 3iB*4-192a;/. 48. ISf-^Sy^-lSy. 70. 3c3-12c3d2_4^2_^l^ 49. m* — 2mw«-n* + 2m»w. 71. pY-277^. 50. a;^ + 125a;/. 72. mV-a^^-m^ + l. 51. m3 + m2w + 2mn2 + 2?i3. 73. aj^ - 25 (a; - 3)2. 52. 24a^-5a;-36. 74. a^-c^ 53. 72a^ + ^x — 4:5. 75. 5m^ — 5mhi~5mn — 5m. 54. (a2-6y-(a2-a6)2. 76. m^-27m2 + 162. 55. ac2 + 7ac-30a. 77. 9 a;^ + 68 a.-^ - 32. 56. x^y^ — a^ — 2/^ + 1. 78. 1 — m^n^ — ph-^ + 2 mnpr. 57. a;* + 4a^-8a;-32. 79. m^-5m2 + 4. 58. 5cV + 35ca^-90a^. 80. m^ - m^x - m -\- x. 59. ac + cd-ab-bd. 81. 24 a.-^ + 43 a;^ - 56 a;. 60. a^ — m^ -f- a; — m. 82. m*—(m — 6y. 61. 9 a;^- 66*2 + 25. 83. Sa}^ + a7n}'. 40 //. C. F, AND L. C. M. 84. 24:€rd'-A7cd-75. 87. a^c + 3ac'-3a^-(^. 85. 16a^-/-9 + 6y. 88. c^ - 64 c^ + 64 a^ - a^. 86. 12a3 + 69a2 + 45a. 89. a^ _ a^ft^ _ 52 _ ^^ 90. 2a;3^3^_3^^3 91. 10 (??i + c)2 + 7 a(m + c)- 6 a^. 92. 100 + 10a;^-25x«-ic2. 93. (m+py-l-2(m+p-\-l). 94. a2 + 2a-c2 + 4c-3. 95. (2m-3)2-6(2m-3)?i-7w2. ' 96. x'6-13a^4-12. 97. m2 + 7i2_(l + 2mn). 98. (c-2d)^-9-3(c-2d + 3). 99. 6c3_25c2 + 8c-16. 100. x^y + y^z-{- xz^ — x^z — xif- — 2/2^. HIGHEST COMxMON FACTOR AND LOWEST COMMON MULTIPLE Rzercise 25 By factoring find the H. C. F. and L. C. M. of: 1. a^-fe^ a^-h\ o>-h\ 2. a^-ab', 2a*-2a'b% a^-2a^b + ab\ 3. a^-16, a'-a-2, a2-4a + 4. 4. m2-3m + 2, m2-m-2, m2 + m-6. 5. «2 + a;-12, cc2-4a; + 3, ar^ + 2a;-15. H. C. F, AND L, C. M. 41 6. o?-^2o?-l^a, a?-6a?-\-Qa, o?-2a^-Sa. 7. x^'-^x' + l, 2it? + 2x'-2x, a^H-2a^-l. 8. a;4 + a^_6, 3a^H-6a^-24, aj^-lOx^ + lG. 9. 2x'-nx-^0, 3a^-25a; + 8, x'-x-m. 10. 5m3-5n^ 15(m-7i)^ 10 m^ - 20 m?i + 10 nl 11. m* — n*, m^ + m?n — mn^ — n^j m* — 2mV-f n*. 12. 5a3 + 406^ 7 a« + 28 a^d + 28 aft^ ^ a' -12 a?h\ 13. c^-d^ c^ + d^ c^ + d^^ (? + 2cd-\-d\ 14. 12a^-30a;-18, 27 a^ - 90 a; + 27, 15 ar' - 42 a; - 9. 15. mn — mp + 2n — 2p, m^H-6m^4-12m + 8. 16. a;'' H- a^2/^ 4- 2/^, 3?z -\- x^v -\- xyz -{- ocyv -{■ yh -\- yH. 17. 12(m«-n«), 18(m*-n^), 24 (m^ - mn + n'^). 18. a^-h^-.o?h^ab, a? -\-W -a?h -al)", a" - ab^ + b* - a^b. 19. a^-3a'-^a-\-12, a'-lSa' + Se, a^ + ^a^- 9a -^18. 20. a^ + 3a^-\-3a + 2, a'-Sa-S, a^ -{-Sa^ + a-2. 21. a3-22a + 15, a3 + 6a2_25, a^ + 13a2 + 36a-20. f Exercise 26 Find the H. C. F. and the L. C. M. of; 1. a:3 + 4a;2 + 7a; + 6, a^ + 4ar^ + a;-6. 2. a:^ + 6x^-\-llx + 12, x^ ^2a^ -6x-\-S. 3. 2a;*-a^ + a:^-a;-l, 2x^ + Sa^ -x^-^x + 1. 4. 3a;^4-3a^-3a;-3, 4a;*-4a^-8a^ + 4a; + 4. 5. 6ar' + 19ar^ + 19a; + 6, 4. x^ -{- S a^ -\- 5 x -\- 3. 6. a;^ + 3«3 + 5a^4-4a; + 2, a;^ + 3a.-34- 6a^ + 5a; + 3. 7. 2m*-{-m^-9m'-\-S7n-2, 2m^- Tm^H- 11 m^- 8m + 2. 42 FRACTIONS 8. 2a* + 5a3 + 2a2_a-2, 6a« + 3a^ + 6a»-3. 9. 3a3 + 14a2-5a-56, 6 o? + 10 a" + 11 a -\-^^. 10. 4m* + 3m3-6m2-29m + 30, A m* - 7n^ - IS m^ + 14 m - 5. 11. 4a« + 14a^4-20a3 + 70a2, 6 a« + 21 a^-12a4-42a3. 12. a^-^a^b-\-6a%^-ah^-6b\ a^ -S a^b-\-3 al/ -2b\ 13. c^-2c3-7c2-|-8c-10, c^ + c^-9c2 + 10c-8. 14. 2 m'' — m^n — 11 mV + 17 mw^ — 7 n'^, m* — 2 m^/i — m^n^ + 4 mn^ — 2n\ 15. a;'^4-2a;--10ic-21, «34.4a^_2a;-15, a^4-2cc2_7 3._-{^2. 16. 2aXa'-2a^-7a'-\-16a + 7), 5 a\a^- 5 a'- 23 a -S), 6a(a3-6a2-26a-9). FRACTIONS I. TRANSFORMATIONS Rsercise 27 Reduce to lowest terms : V a^ + 27 ^ r2a^-x-6 ^ a;^-81 0^2-9 12i»2-13a; + 3 aj^+lSic^+Sl Ax' + ^x + l 3?^ -6 16 - (m + ny 5a;^4-5 ' ' 6m^-24* * {m-Af-n' 2a^- 2a -12 a44.ft3^^2_^q_|_]^ • a'j^2d'-a-2' ' a'-l ^ y? + m.r 4- »-« + 'nin -- 7j^^— 64 ^ a;2-h3mx + 2m2 * * m^+2m3-8m-16* 4m^— 8mnH-4n^ 12 m^ — m^^^ 4- m^n — ti^ FRACTIONS 43 14. 15. 16. 6 ac — 2 ad — 3 ?)c + hd 9 ac — 3 ad H- 3 5c - hd (m 4- ^)^ + 7 m + 7 n + 10 w?-\-2mn + 'n?- 4(m + n) — 12* ,^ 10a^ + 5a;^-105a:3 ^, a^4_7 ar^4.12 a; + 4 24 a;^ -64a;3- -24iB2 m'- in^ — ^m + 3 2' m^ — m — 1 :^- lla; + 6 18. """^ » 22. 8m-3 19. ^^ ' Jl ' 23. a^_l_2aj2_7a;_2 x3_20a>+33 a;*-14ar^ + l 2-5a-4a^+3a^ 2^ 5m^-5mV 4-|.4^+9a2+4a«-5a** ' 2m«-2m2w + 2mn2* Exercise 28 Change tci mixed expressions : x-\-2 ' ' x^-^x-S B2_12a;-47 ^ 4 a^+12 a;3_^^4 2. a; + 3 2a;3 + 7 a^_2a^4-4a;-l ^ fl^-a^ + 3a; + 2 iC- -3 3a3 a — b 9. m^-\-2 10. m^ + m — 1 x'-\-3 x'-^x-l ' x'-{-2x + 2 12 2 + a;-a^ 7. .^. 9. „ ^ .. 11. "^ 19 1 12. — =— to 4 terms. 44 FRACTIONS Exercise 29 Change to improper fractions : , ^ x — 1 e 2 2 I in^nHm + n) 2. a — Sc-\ — • 6. (c-\-d)^—^ ^* a + c c-\-d 4. 1 a^ + ft^ •• ^ ^ ' ^ a + 1 (a-^by 8. ^^(^' + 3) 2. 9. m^ — 2 mn +2 m - 71^) 4- m V 2m?2+7i^— »^ ,„ -, , / 9 I I 1 \ 10. m-{-n—p — ^- 13. l + (ar + a;H • m + wH-p \ x^lj !b2+3x-2 L V ^ /- 12. a+2-^+6^+a'. 15. (''-^-A+^ + 2. a + 4 V=" + l / ie.l-[.-{2..^-^i)i--.)]. 17. 3m-r("^ + 2X'^-^)-(-»^ + ^)1-(«t + 2). m + 3 ^ ^ 18. a'+r-'»6-a'+(-a' + «6)-&n I „ ^, a — 6 19. (a-6)»-r(a + 6) + 3«H&-a)+a(«'-a)-n Collect : FRACTIONS 45 11. ADDITION AND SUBTRACTION Exercise 30 1. 5^4-3^ + ?. 12. ? + -^+ ^ 3 4 2 a a+1 a-1 2 4a;4-l . 2a; — 1 ^^^ __a ^ _^ 1 4 3 a-1 a + 1 a'-l 2a; + l a?-l 14 3 5 2 m- 3 ' 3a;2 2a;3 ' * m m-1 m^-l* ,1.1 ,,^ 2 3.1 a; (a; 4-1) a; (a; — 1) 3 — 3 a- 5 — 5a l + a 2 , 1 1 ^^m — n.n—p.p — m 5. -H -— r -• lb. 1 i a; — 1 a; + l ar — 1 mn np mp g + l ' g- 1 --, 4a — 6 18 a6 . 4a+ft * a-1 a + l' ' a+2 6 a2-4 62 a-2 6' 7. a + 2 a-2 18. "^ "^ ^ ^ a-2 a-\-2 a^-1 a;-l „ 5a + l 2a + l ,« c^ + c?^ c^ d^ o. — -— • ly. aH-3 a-3 cd cd + (P cd + c^ 9. ,^±4_ . ^^. 20. -^-^^+-^ + . 1 (a-c)2 a'-c' a^^x-\-l x-1 sc^-l 6 ^Q (m + ny _ (m-n)\ ^^ 1 1__^ m — n m-\-n a^+2x-{-4: x—2 oc^—S 11. -A_ + ^_ + ^. 22. 2^2m _^ m+l 1 m + 1 m — 1 m — 2 (m— 1)^ (m— 1)^ m—1 46 FRACTIONS 23 a+r. a-m ^^_ a^^_a_^ ar-{-am-\-7rr ar—am+mr a -^2 a — 2 25. -^ + 2--i-. 28. 3c--^ + -i-. x+1 x—1 c+1 c— 1 30. (ra+-J^\-U+-J^\ 32. 2-^+^+^ \^ m—nj \ m+nj \^—y ^+y) x^—y^ 33^ K + ny _/m_^7i_^^ mn{m — nf \n m 31. ^±1_24-^^- a;4-2 a;-4 34 a? — 3a , 9aa; , 1 ic2_3aa; + 9a2 a^ + 27a3 a;4-3a 35. 4J^ + ^ + J^. 36. ^+ 3 1 a^-1 1-a a + 1 2-a a-\-2 a^-4: 3^ g + l 4 g-l a + 3 9-a2 3-tt* 38. 1 + -J^+ 2 2 3 X a; — 1 l—a^ x-\-l x-\-7? 39. _A___1__^+ -8 3m4-15 125-5m=^ 7m-35 40 ^ — 5 I ^ + 5 . 21m 5 + ^1 5 — m m^ — 25 ., 1 , 20a , 2 1 a l-lGa'' 8a-2 a + 4a2 42. 1 +6-^ + FRACTIONS 1 47 a^3 ' S-a ' 9-a2 2 Sx' 4 43. 3x + 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. x-S x-\-S 9-«2 m + 1 1 m^ H- m — 2 m^ + m + l m — 1 1 — m* c — a? c + <? _ • (d — c)^ c + c? c — a; {c — x)(c — d) x — Sa 3ax~2y? 1 ar^_3aa; + 9ci2 a^ + 27a« 3a + a; a+1 , a+4 (a-4)(2-c) (a-l)(2-c) (m — n) (m — p) (n — p) (n — m) (p — m)(p — n) x" + 2/^ + (a; -2/) (a; -2;) (y-z){y-x) (z-x)(z^y) m + 1 m-1 2 + m^ — m + 1 m* + m^ + l m^ + m + 1 -1— f-i L_l _^ [o 1 ( 1 , ^ \\ x + b \ x-n \a?-25 x-5)] \2x + 2-(^ l_^1_-2^_ (1_^__A_2^ -J— f-J— (^ ( 1 +^-M1 1-x [x-2 \&-x-i? \2-Zx + ii? x-X)]_ 48 FRACTIONS III. MULTIPLICATION AND DIVISION Exercise 31 Simplify : 1. m^ — n^ m^ w? (m — Tif ^2-144 a + 3 a2_9 ^_^i2 w? — n^ m^ — mn-{- n^ m-{-n m^ + n^ m—n 7nf-\- mn + n^ (c 4- df ^ c'-cd + dj' c3 + (Z3 * c2-f-2cd + c«'* m2-2m + l (m 4- 2) (m - 1) (m + 3) (m - 2) ' m-\-n \n m) mn /m + ^^ j 7n-{-n\. n m — > c-d ' c^-d^' (? + df 10. (^^/-^j(^^2(^2/2_^i) + i)- a^-{- {m +p)a + mp a^ — n^ 12. fg-Sm + mAfl+i + i-T— — 4^— — l- FRACTIONS 49 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 3 (m — yi) m^— {p — 5)m — 5p ' m-\-p m(m^-\-5m) m^ -{- mp — mn — np m—p a^ + ac + ab + he ^ g? + «/+ «cg + df (J? -\- ac -^ ad -^ d/: c? -\- od -\- ab -^hd m-\-n .m A _^ fm-^n _ m — rb \ i) ' \m — n m-\-nJ + d c-(A /6 3 S y — d c + (ZyVc c — d c-\-d) m — n m-\-n^ 'c + d c — c m^-9 ^ (m-4)^ . |^ m^-7m + 12 7/i + 4^ * m + 3, 6 a2-2a-3 a^-g + d c — d\ — d c-^dj a^^a-2 a^-2a + l c2 + d2 1^- 4 m^ — n^ —p^ — 2np_^ 2m — n—p A 7n^ + n^ — p^ -^ 4: mn 2m-\-n-{-p a^-5a;-f 6 ^ a^4-a;-2 . a;^-4a; + 3 a^^Sx + 2' x' + x-e ' arH-4a; + 3* (-•D(S-')H'-?> 3 cd(d -c) + (^-d^ r dF\ . c^(c-cg)^ (a_cy-&2 (g + & + c)' (g + cf - b^ (5 + c)2-a2* la-i-by-c"' a^-(b-^cy' Tin} — 2 w^v? -\-n^ m^ — r^ , in m^ + ri" tti^-mH^^-n'' ' (m^ + w«) (m^ + n^) 4 R. & S. EX. IK ALG x{x — 1) + 1 50 FRACTIONS 27. f£_Ji-^-2Yl 2^Y \yz xz xy xj\ x + y + zj 28. f™-i2iY^r('-+— -4Y-+— +4\ \n mj [\n m J\n m j 29 (c + d)^-4 d'-{c-2)^ . c^d-2 ' 4 - (c - d)2 (^-{d-\-2f c-d-2 "■ [e-'-'-?)-e-'-^)]*[('-^)fe)} [_\xy xz yzj xy J Simplify : 1 1. — X + 1 lY. COMPLEX FRACTIONS Exercise 32 a4-2 4. a-3 "^ 16 ^ a? 8 10_3 X* a^ sc^ m + 2 2. 3. m m-3 + - m a + l 4 a; a^+l 1 1 ajH-1 x-\-l — 5. a; + 4 — « + a; + 2 . X — x-^1 8. d' c" i + i+1 m n p n p 771 FRACTIONS 51 x^ — x — 6 10. -o — 71 ?r- 11 12. 13. a^-x-6 • a.'2-6a;-7 c—d c+d c+c? c — d c'-d' ^ ic-df 2 3 a; -14 a & a 6 16. 1- 4a ^ 2m , , _J__\ Vl+J- 2m + V 18. 2m 2 1 — a; (f-')-(f-') I4.I i_l 20. a + =— . a h a h a-\- 1 4 . • 1 & , a h a a + - a ft^ + a-2 3fa4.2)-2(a + l) a2_2a-3 . 15- 2 ■ Q^_i_9 ~^' 21. tt2_4a4-3 10 10 2^- a? a3 + 64 a^- .4a« + 16a2 m + 1 m + 1 1 5 5 m + l v2 ^^' a? , g^c + Z * ^ + ^-^ ^z-c+(^:r^2 100^+9^-63 52 FRACTIONS 24. 2a + 3a + 4a-l 26. 1 + 1 + l-x 25. 1 + 4 wn (m-2nV 4?nri 1_^ 27. 1 1 1 a-?> aH-6 b' — a^ 264-1 a — b 28. 29. m^ — 71^ (711 -\- 7i)(m — p) m? + 7i^ m^ — mp — mn 4- np \n'' m?i my \7r mn my l+3a l-3a l-3a l+3a 3a 1 3a l+3a l-3a 30. np mp 1 mn (m- -P)^- -ii^ 1^_ np 1 mp 1 mn 31. a/*^ + mx + nx-\- mn x^-\-nx — px — np a? + mx — nx — mn x^—nx -\-px — 7ip 32. 14- c3 1- 1-f 8c3 1-c 1 + 2c 2c 14-2C 33. rx + yV ^ /x-yy x-y V / 'x + y V 34. m4-n ■ m^ + n^ ' m — n m' m^ 4- ^i^ + n m' FRACTIONS 53 35. 36. (m — n) (m + p) (m -f- n) (m — p) {m — n)(m -\- p) {m + n){m — p) 37. 3a; — 1 X 3 "^4 ^-l(x+^^-)-\-2x 38. 1 _ ^ + ^ ' I _ c^ + ( ?" 39. 2mn 4:mn m^ — 4 wm + n^ -r- 14 m?i . \ mn J 40. i_i i_jL,i ' ah a"- a b X + 11 62 a6"^a2 62 -a^ a'b^ 41. r46(a + 26) J (a3-86V 1 |_ ft-26 JLa^-8q262_^l()6^J a2 4- 2 ty6 + 4 6^ a + 26 (m^ -\- n^)(m — n) m^ — mn + 71^ m^ — 2 mr? (m — ny m^ H- mw + n' 54 FB ACTIONS 43. 44. - (»--)f'+-y ^ 1+ a 45. Find the value of 1 when a = x-\-l. a a^ — b^ 46. Find the value of — when a = ic + 1 and b = x — l. 47. Find the value of (m-iy-(m^-l) ^hen m = a + l. (1 — my 48. Find the value of a-\-m , a — m Sam _. „^ _ 3a 1 when 7n = — • a — m a-\-m cr — iiw 2 49. When m = - and n = ^ find value of ^>^' + mn - 2 7i^ ^ 50. Ifa = ^^and6 = ^^,findvalueof ^i^ + 1 ^~^ iC + l x-\ a — h a + h x-\- 51. If a; = a — 2, find value of x^l -1 a; + + 1 52. If a = m and 6 = w, show that x-1 a + h a — h 4 mn a — h a + h w? — r^ 53. If a = -T-^ and c = . "^^ , find value of a in terms of m 1— c 1— m and reduce to simplest form. 64. If a; = -^ and y = -^; show that ^"^ 2a6 a-f-6 a — h y? + f (x^+^ FRACTIONAL EQUATIONS 56 FRACTIONAL EQUATIONS I. NUMERICAL Exercise 33 Solve: 2 a; a; a; 1 8. ^--l + 5-^- + 2. 3 5 2 6 3 2 2 ^_? = ^ + ?. « 4a; + l , 2a;-l 3^ + 3 * 3 3 5^5 ^' '~S~^~~~2~~'~2~' 3. 1 + 1 = ^-1. -^ 5a; + l , 3a;-2 _ l + 8a; . 5 3 15 10. —^--^-^ — ^— . * 3 2~4 3* „ a;4-l a;-l _ 3-a; ^ 2 a; , a; a; 11 /^ 6 ^+l4.^±^ = 2. • 2^4 11 12. 2(a; + 3) 3(a; + l) ^o^ 5 2 13. i.(a; + 2) = i(a;-3). 2a; + 3 a;-l_o 11 ^ 3 14. ^(a;-l)-|(a;4-l) = 0. 15. |(a; + l)-f(aJ + 2)=i(a; + l). 16. (a; + l)(a;-i) = a^. . 17. |(2a;H-l) + 2 = ^(3a;-2). 18. ^-i(. + 3) = ^-3. 19. a;-J3a;-i(a;-h 1)1=0. 20. i[a;-(2a; + i)] = i(a; + i). 56 FRACTIONAL EQUATIONS 23. 2__ 3 24. fe^V(£=31^=.(5.^-l). 25. 2i-|(a^ + 3) = l|^+l-2^. o o 26 fe±D-i(^±ll = 31 ^^'-1 ^ 3a; + l 3 2 ' * 4a; + 3 6a; + l 27 -A_ = _3_. 32 3a;4-2 l^o;-! ic + l x-{-2 ' 4.x 4 ic + 1* 28. _i- + 2 = ^^. 33. 3a^-l _ 2a;-3 a; + l x-1 ^x + 2 Qx-\-5 29. ^±1 = ^^. 34. _L-+-i- = l ^ a; + l a; + l x-l x^-1 30. ?^-l = ^Zl3. 35. ^_+ 3 0. ic + 2 a;-2 x-2 x + 2 3^-4 36. 3_^— A_ + i= 9a- 3a; + l l-3aj 9iB2_-L 37. ~i- = -J^ ^ 38. ? + — ^L_ = a-'^ + l x+1 x'-x + l ar^ + 3a;H-2 (a; + 2)2 39 a;^ + a;4-l ^ a:^ — a;4-l . x x + 1 x-1 "^l-ar^* . 40. FRACTIONAL EQUATIONS 67 X 5 a?^ X 3a;4-6 6^^-24. 2ic-4 41. „ ,^ ,+ 2 1 2a;2 + a;-l a!2-x-2 2ar'-5a! + 2 43. ^ l- = ^i 1-. a; + 2 x-\-3 .t + 4 a;-f-5 44. -1,+ 2 3 45. 46. 47. 48. x-\-l a^ — 1 1—x 2 03*^ 3 a; x a^ — 1 1 — x x-{-l 3 4.2 2a; + l 4a;2_-i^ l-2x xj-3___2_^a^--l a;_2 ic2_4 2 + a;* 3 2 5 x-S l-2a; 2af-7a;4-3 4a; + l ^ 3 _ 1 +4a; ^ x-^2 ~a^-4 2-a; * a;+5 5 — X 25 — a^ 51. ^ 4 3_^o 2(2a; + 5) 2a;= + 9a;+10 3a; + 6 52. -^- + 5^ = ^-+1. x-32(a?'-»-6) a; + 2 58 FRACTIONAL EQUATIONS 53. ^ + ^^ = ^_ 6a;-6 3-3a; 2a; + 2* 64. 2a;-l 4a;-l .^ ^ -18ar» 3a; + 4 6a;-l 21a;-4 + 18ic2 55. 2 _ 3__^ . 1 a; + 3 2(aj + 3) 3(a; + 3) 4 _ 4a^-2a ;4-l . 4a^ + 2a; + l . 2x-l ^ 2x^1 ^^ Sx-2 , 2x-l X 58. 6 2iB + 3 2 3aj + 5 2a;-l 2ic 18 x-\-5 12 59 a^ 4a; + 5 _ 2a; — 1 3 2a; + 4~ 6 60 ^^ + 13 6a;-1 ^ 3a; + 2 8 3 a;- 9 12 ' 6 9 a; - 36 6 62. ^+^i- ^-2 -^J-l 63. 64. 66. 9 3 a; + 11 9 li a;-l a;-3 X - -4 a; -2 a;-2 a;-4 X - -3 X -1 2a;-3 3a;- 1 x-^1 2 4 5 4 1 5 3 3 2 a; -3 3a;- J._ a; 4-1 1 = — ^BACnonAL EQUATIONS 6^ II. LITERAL Exercise 34 Solve: 1. 3a; + 5a = ic + 8a. 6. ^ax = h{x-\-a). 2. 2a'4-4a = 3a; + 3a. 7. 2(x^a)=^{x-a). 3. 3x + 2a = 4a; + a. 8. (x + a)^ = (a; — a)^ + 4 a. 4. 3aa; + 4a = aa; + 10a. 9. (a; — a)^ = (a; — 6/ + al 5. 3aa; = a(a; + a). 10. {a — h)x + {a + h)x = a?. 11. (a + 6)a; + (a — &)ic = «^ + ca;. 12. (aj + a) (a; — m) = (a; — a) (a; 4- m). 13. mx (x + m) + 7ia; (a; — m) = (m + ?i) ar' + w — n. 14. a6 — (a — 2 6)a;=(2a — 6)a; — 1. 15. (x + 2a+by-(x-h2ay = b(Sa-^5b). 16. ^ + ^ = 3. a 2a 17 ^_?^ = 1. ^ * a 3a 2 18. 'i^' + !^ = m^ + n^ 19. i + l = l_l. m a? 71 aj 20. ca; + a + - = -- c a 2\a J S\a 1 . 22. x-\-m 3 a; — 71 4 23. 4 3 m + a; tti — a. 24. aj + d^ g a; + c2 d 25. 771 + 1 7/1 + a; 771 — 1 m — X 26. n(a — x) t\ m — -^ ^ — a = 0. 2a-a; OT 9 5 m4-7i — a; 77i — Te + a; 60 FRACTIONAL EQUATIONS 28. nk+Jl^^LlzJl. 30. X — 1 X -\-l '" ^ 31. ««7. m m- -n m-\-n 30 a; + n _ a; + 2m 33. 2a;-a X — a 34. 2x-a x+b m-\-x 0? — 6 35. 2 m — x 2 1^ 36. 1-^ 1+^ 1+^ m 1-5 m m 37. m-f 1 m — 1 2 ~ ' 4 m + a; a? m — x m^ — x^ ab -{-X ^ ab — X y? — a^l^ 3m 3a; + 4mH-2n x-{-l 41. t^Lzl^ = 4^Hhl^. i«H-faJ -ia-fa; 42. a; + a _. a^ + « + l . ic — a a; — a — 2 43. ^ — 2'^ m + 4a; ^^p m+a; m — x . x + a _ x 4- c a; + c a; + a 45. E±^_^LL^ = o. a; — 5 a — 6 c+2aj 4a^ 46. c — 2a; 4a;^ — c^ x m m — n . m 47. 1= — OQ ^x — a _o b — x m-\ ^— ^ 5a;-a ^ a-10a; 43. ^ !L_ = '?Lz: • 2x-a a-4a;* * a;-m a;-n x .f. X . a nx ._ 2a;— m x-\-2m , 5m ^ 40. 1 = • 49. ' 1 = U. m + n n — m w^-v? 2x-\-m x—2m x SIMULTANEOUS EQUATIONS 61 SIMULTANEOUS EQUATIONS I. NUMERICAL Exercise 35 Solve: 1. 5x-{- y = ll, 5. x + 3y = 5, 9. 5x — y==16, 3x + 2y = l. 3x-{-4:y = 0. x = y. 2. x-{-2y = S, 6. x-4.y = 7, 10. a; + 82/ = -20, 3x- y = 3. 4.x- y = 13. 3 aj + 4 2/ = 0. 3. 2x-\-3y = 16, 7. 2x-13y = l, 11. aJ-2^=0, 3x + 2y = U. 3x-21y = <d. 4a;-5y-h2=0. 4. x-\-2y = 3, 8. 2x + 3y = 4, 12. 4a;- 2/ = 10, 3x~ y = 16. 6x- y = l. 72/-2x = 12. 13. y — x — l = 3, 15. 5 x-3 :2/-72 = 5y, x—5=-y X -1 = = 15y. 14. 3x = -2y, 16. 5 x + 3 2/ = 102, x = 35-{-lly. 7 2/ + 3 ia; = 104. - M=^' 19. 1-!=^' 21. x^y 2 3' M=^- | + . = 9. i+i-»- - M=-^' 20. X y_7 3 4 4' 22. hh-^ X y 5 . 3 2~ 6* 5 3 5 - 3 2 9 62 SIMULTANEOUS EQUATIONS ''■l+t'' -1-1=^' -T-H' 3 4 4 2^3 2 3 ~ ^' 26. ^ + f = -3A, 32. .-^ = 2 + 2(.-,), 33. 2x y 3 3 1 3' 14 ^ a; = 7' 32/ a^ 5 8 -k- 2a;4-3 5y-S -2, 7 4 i(142/- ox 160^- 23 * 2 3 -^' 3a; + l .2/ + l_i 4 3 a; y .3(0^ + 2/4-1) 3 2~ 4 !-«= = 1 + 12, aj+2/ 5 35-2^ a; a; "3* x + Sy 3 -2 42/- — x + 5 5' ' 3a;-2/ + 7 2a; + 32/ ' + 1 10 12 5 2 34. 35. -, 4a;+82/+l 7a:-22/-l 2x+4:y 5x-^6y Ay se. ^-^t.=(2.-|) <?o 6 2/-1 , 3a; + l _5 30. — - — + — ^ — -^, 3^+1^14 5a;-l 2/ + 3 , I^a -22/ 5* 4 7 "^3 ' a;+2 y-2 Sjy^Ax) ^^- x-y'^' ^^' ~S 2- = — 4 ' y X X y 4 2 5 3 _41 2 ^3 ^^^ -' 3 5 ~60' ^_5=^-3(2/-a.) SIMULTANEOUS EQUATIONS 63 38. -^_=_-^_, 4a;-3(a;-?/) _^ ., x-2(x-\-y) 39. (a; + 3)(2/-l) = (aj-3)(2/ + l), a^-^ + i^ = (.-3)(, + l) + llf .^ 4aj-3 . 2x-3 Qx-l 40. 2 r Sx-2y " 3 ' 52/- 1 x + 1 15^-10 3 3x-y 9 2x 3 Sy 5 x-h2y 4 =3--7 6y > 1+^ ,_S \x-y 5 -^+t 41. 2a5-2/ + 3 05-2^ + 3 3a;-4y + 3 _ 4a;-2y — 9 4 ~^ 3 ' 43. (K 2/ 45. 5+5=2, a; y 47. X y a; y a; y i-l=o. a; 2/ 44. 13 5 25 2/ 2' 46. 3 2 31 a; 2/ 40' 48. 1 1 _ 5 2x^Sy 12' ? + l- = -2. a; y 5_10_11^ X y S' 111 3a; 2y 12* 64 SIMULTANEOUS EQUATIONS 49. ^ + ^=1, 51. A + X = _2, 53. 1^-A = _A, 2x Sy ' 2x 3y ' 3x 2y 36' X 2/6 4:X Qy ' ■ 8x62/ 24 50. A + A = _??, 52. ?_5 = _4, 54. Ah_A = 8, 3a; 22/ 3 a; 2/ 2a; 42/ ' 2a; 32/ 3* x y ^* 3x 2y 3* 4a; dy 3a; 22/ ^ ?_ = 22 -62/ + 4a; = 26a;2/. 3a; 32/ ^' 3a;-5 , y-1 /3a;-l\ , ^ — 2 — + 3" ^^-y- 2/f— 3 — \ = xy-x-\-6. II. LITERAL Exercise 36 Solve: 1. a; + 32/ = 7a, 5. x-\-y = m, 5a; — 22/ = 18 a. 2a;— 32/ = w. 2. 3x-\-2y = 5a, 6. a; + 2/ = '^ + ^> 5a;-f32/ = 8a. 3a; — 22/ = m — ?j. ^ 3. aa; + 62/ = l> 7. x — y = m — n, ax — 6y = 3. nx-\- my = 2 mn. 4. 2aa; + 3&?/=l, 8. ax-\-hy —ntj 3 ax-]- 2 by = 2. ex -{- dy = n SIMULTANEOUS EQUATIONS 65 9. x-{-my = -l, ^^ (7n + n)x-\-(m-n)y ^^ y = n{x-\-l). ' m'^ + 7i^ 10. mx = ny, x-\-y = a. 11. {c-{-d)x=(c — d)y, x — a = y. x — y = 0. 13. (711 + n) X -{- cy = 1, ex -\- (m-\- n) 2/ = 1. 14. ^ + ^ = c, a; 2/ X y X y _ 3cd — c^ ' c-\-d c — d c^ — d^' x + y = c. 16. i^ + - = a + &, ox ay X y ^ • y ^ ^ 25. (g + ^>-(^-^)y -i^ ma; — ny = m'-^ + w^- 20. (a + 6)x+(a-6)2 21. a c x-\-l 7/H-l ^ n — J- c a 22. aU-^a-,-^^ ah 23. x-\-y , x-y ^ i»-?/ « + ?/_n m n 24. 2' + »-« = 3a. 17. -^ + - 4ccZ X . ^ ^ 2 (£zi^' = l.. + m — n m-\-n m^ — n^ (c + c?)2/ 18 ^+^ ^ ^-^« 26. ^-^ I y-'^ =i ' y + a y—2a ' p—m p — 7i x — a __ x-\-Sa x + m . y— m _ m y—a y+a ' p m—n p R. & S. EX. IN ALG. — 5 66 SIMULTANEOUS EQUATIONS III. THREE OR MORE UNKNOWN QUANTITIES Zizercise 37 Solve : 1. Zx-\- y—2z = l, 9. x-\-y = 2a, 2x-3y-{- z = -l, x + z=3a, 4:X—2y-\-3z = 14:. , ^ ^ y + z =2a. 2. x + 3y+ 2 = 1, 2x+ y-3z = l, ^^' ^ + 2y+ z = a, 3x-^2y-2z = -2. x+ y-^2z = b, 3. 2x + 3y-5z = 0, 2/+ z + 2x = c. 3x-4:y-2z = -3, 2y-3x + Sz = 7. '^' o^ + 20 = 2(, - .), 4. 2. + 3, + 4. = 12, y + 20 = 3iz-x)^ 3a.-42/ + 5. = 2, . + 20 = 2(.. - 2,). 4:X + 5y-\-6z==24.. 12. x + y-^z = a-\-h, 5. 3a;- y-{-2z = -ll, x-^y-z = a-b, 3y + 2x- . = -12, 2/ + ^-^ = c-a. 32!+ x + 2y = -20. 6. 2a;4-2/-10;2 = 20, 13 ^4.^ + ^ = ^ ^ , Q 1K 3^2^4 12* — y — oz-\-3x = lbj ^ 4^3 2 12' 7. x + y = z + 3y X y . z _ 5 y = Sx-8, 2~4 + 3 2 2 — a? = 4. 8. x + 2y = 25, ^^' 1^; + J2/ + J. = 23, 2/-22; = 0, icc + iy + i2 = 28, a; + 30 = 2O. ix-\-iy + ^z = 27. SIMULTANEOUS EQUATIONS 67 ''• 2 + 2/ 5' S+z f z 2 4 + a; 3' 16. ay + hx = l, ex + az= 1, bz + cy=l. "• A+ft-^ X x + y-\-u = SAf 2/ + z + w = 36. 20. 1.2 1_^ X y z 2_4 + 3^_3_ X y z ?_l+?=i X y z 2' 21. _ + - = w, a? 2/ a; z 2, z 2|, 2* 32/ 2 1+1+ i=r. 22. i5+§_§=4, X y 2z X y z 9 4 4. 18. a; + 2/ + 2; = 33, -"7, + ^"=^' X y z + z+u = S5, . ? +5-1 = 2. 352/ - .o 1^1 ^ 23. ^^ = 7i, 19. _ + _ = -, x — y X y Q 1_^1_7 -^==li ^ + ^"12' 1 + 1 = 1 -^^=^i- a; 2 4 2/-^ 68 SIMULTANEOUS EQUATIONS 24. " + -^ + 5 = 1 X y z 2 25. mx + ny = a(m-{- n), mx -\-az = n{a-\- m), a . b c 1 26. ny -\-az = m(a + n). x + y=22, ^_^_£— _ 1 2/ + ^ = 18, X y z 2 • 2; -j- W = 14, W-\-U = 10f w + a? = 16. IV. PROBLEMS IN SIMULTANEOUS EQUATIONS Exercise 38 1. A man purchased 20 acres of land for $1640. Part of it was bought for $ 90 an acre and the remainder for $ 50 an acre. How many acres were there in each portion ? 2. A man and a boy together weigh 230 pounds, and twice the man's weight is 60 pounds more than 3 times the boy's weight. Find the weight of each. 3. Three horses and 4 cows can be bought for $610, but at the same rates it takes $720 to purchase 4 horses and 3 cows. Find the price of each per head. 4. If half of A's money is added to B's money, the sum is $ 170 ; but if half of B's is added to A's money, the sum is $ 160. How much money has each ? 5. In 10 hours A walks 1 mile more than B walks in 8 hours. In 5 hours B walks 5^ miles less than A walks in 7 hours. How many miles does each walk per hour ? 6. If the numerator of a certain fraction is subtracted from the denominator, the remainder is 21 ; but if the denominator is subtracted from 8 times the numerator, the remainder is — 7^ Find the fraction, SIMULTANEOUS EQUATIONS 69 7. In a certain town meeting 312 voters were present, and a motion was carried by a majority of 8 votes. How many voted for and against the motion ? 8. Two men had together $ 100, and if the first had given $ 10 to the second, each would then have had the same amount. How much had each originally ? 9. If 2 is added to both numerator and denominator of a certain fraction, the resulting fraction is |. If 1 is subtracted from both numerator and denominator, the new fraction is ^. Find the original fraction. 10. A boatman can row 20 miles down a stream and back in 10 hours, the current being uniform. He can row 2 miles up- stream in the same time that he can row 3 miles downstream. Find his rate per hour both down and upstream. 11. If the width of a field were increased 1 rod and the length 2 rods, the area would be 34 square rods greater ; but if the width were decreased 2 rods and the length increased 3 rods, the area would be unchanged. Find the length and width of the field. 12. Find a fraction such that if you double the numerator and add 3 to the denominator the result is f ; but if you add 3 to the numerator and double the denominator the result is |^. 13. Two sheep-owners met. A said, " Sell me 4 of your sheep, and I shall have twice as many as you have." B said, "No; sell me 1 of yours, and we shall each have the same number." How many had each ? 14. When a certain number of two digits is doubled and in- creased by 4, the result is the same as if the digits had been reversed and this number decreased by 22. The number is 2 less than 3 times the sum of its digits. Find the number. 70 SIMULTANEOUS EQUATIONS 15. If I divide a certain number by 3 more than the sum of its two digits, I get a quotient of 3 and a remainder of 8. But if I reverse the order of the digits and divide by twice the sum of the digits in the same reversed order, my quotient is 3 and remainder 11. Mnd the number. 16. A boy bought 5 apples and 3 oranges for 25 cents, 4 oranges and 5 pears for 35 cents, 2 pears and 7 apples for 20 cents. Find the prices paid for each apple, orange, and pear. 17. Find 3 numbers such that if each be added to | the sum of the others, the results will be 32, 28, and 30 respectively. 18. The sum of the three digits of a number is 12. The hundreds' digit is one half the sum of the other two, and the units' digit is ^ the number composed of the other two in the original order. Find the number. 19. Three boys together weigh 300 pounds. Half the sum of the weights of the first and the third equals the weight of the second. The sum of the weights of the second and the third divided by the difference between the weights of the third and the first gives a quotient of 5 and a remainder of 20. Find the weight of each. 20. A and B together can do a certain piece of work in 3 days, A and C the same work in 4 days, B and C the same work in 6 days. How long will it take each alone to do the work ? How long will it take all working together ? 21. Some books were divided among 3 boys, so that the first had 12 less than half of all, the second 1 less than half the remainder, and the third 17. Find the number each received. 22. A boy has 100 pieces of silver. The value of the quar- ters is 3 times the value of the dimes, and the sum of the values of the half dollars and dimes divided by the difference of the values of the quarters and half dollars is f. Find the number of dimes, quarters, and half dollars. INVOLUTION AND EVOLUTION 71 INVOLUTION AND EVOLUTION L MONOMIALS Exercise 39 Write the value of : 1. (2a)l 9. {-2mn)\ ^^ (Sa^\ ^1. p^^V. 2. (3 ay. 10. (-2 ay. ^ ^ ^ ^- ^^'*^'- 12. (^m'ny)\ ^g. ^-^^^Y. 23. ^^^'^'^* / 2 am V V 3cdy ®- ^~-^")- 13. aaO^ 7. (Say. ' \S 20. -f-^X 25. r^^^Y. 40. ^S2a'' 8. (-2a2)^ 15. (-^aby. 26. V4m^ 34. -y/lQ m*n\ 27. Vl6mV. 35. ^Wm^n"^. 28. ^8?d^. 3e. ^/4^. ^1- \'^K^J 29. ^27?. 30. V64mV. ^ 42. A^/-32'''''^''" 31. ^327^. ^^ ^/25^ 43. V-27(a + 6)^. 32. VlOOa^y. 44. ^Sl (m-ny. 33. ■v/-64a^c^ ' >'343ci2 45. V-32(a + l)' 72 INVOLUTION AND EVOLUTION n. INVOLUTION — BINOMIALS Exercise 40 Expand : 1. (a + by. 12. (d^- -4 c)*. 20. (- -!)• 2. (a + by. 13. (d^- -3 c)'. 3. (a + m)^ 14. (c^-\-2cy. 21. (aH -a^-l)^ 4. 5. (a + 2y (a-sy 15. 22. i^- 3 a; + 2/. 6. (2a + 3y. 16. (2 a -I)'- 23. (m*- -7l2_3^^\ 7. iSa-2y, 17. fab \' 24. K + ■ a + 1)^ 8. (2a2 + 5)^ 25. («=- ■a + lf- 9. (ab - ly 18. V2"' -')■ 26. (a + c-i)'- 10. 11. (a-2y. (a'b'-{-2cy. 19. (i- -11- 27. (2(1- -a'-\-iy HI. EVOLUTION — SQUARE ROOT Exercise 41 Extract the square root of : 1. aj* + 2a^ + 5aj2-t-4aj + 4. 2. x*-6x--{-17x'-24:X-\-16. 3. aj« + 2ar^ + aj'-2a^-2a;2 + l. 4. a;^_2a;3 + lla^-10a; + 25. 5. a^ + 4:a;*-8ar' + 4ar^-16a; + 16. 6. 4a;*-20x3_,_37 3^_3Q^_,_9 INVOLUTION AND EVOLUTION 73 7. ^-12x-2x'-\-4.s?-\-Q^. 8. a^ — 2 a^x + 5 aV — 6 aV + 6 aV — 4 aa^ + a;«. 9. 12a;3-30a; + 4a;^4-25-llar^. 10. 25 a;2y _^ 2 a;y H- x« - 8 ary- 12 a^?/^ + 36^^- 4 ar*?/. 11. ar'-2ar^-14a; + 49 + 14x^4-a^. 12. - + X^+ 3 +T+9 13 ^'_i^4.??^ + a; + i. . ^^' 9 3^6 ^"^^16 14. ^ + i^+2-i^ + 4 15. 4 + 4a-a^ + -+ — -- + -. 16. f + 4 + 6_i_2a. 9 Of a 3 17. c«-| + ^*-f-^' + <^ + f^-- + Ti-,- 2 16 2a 4aa4a^ Extract, to three terms, the square root of : 18. 1 4- 3a. 20. a^ + 9 &. 19. l-5a. 21. a^+4a;. Extract the fourth root of : 22. 81a:4-216a^ + 216a^-96a; + 16. 23. a^-12a362_^54a26*-108a6« + 8168. 24. 16a^ + 16a»a; + 6a2a^ + aa^ + — . ■ 16 74 INVOLUTION AND EVOLUTION IV. EVOLUTION — CUBE ROOT Exercise 42 Extract the cube root of : 1. a3 + 9a2 + 27a + 27. 2. a«-15a^ + 75a^-125a» 3. a« + 6a^ + 15a^ + 20a3 + 15a2 + 6a + l. 4. 1 - 9 a + 33 a^ - 63 a^ 4- 66 a^ - 36 a^ + 8 a«. 5. 60 a^ 4- 1 + 240 a;^ + 64 cc« - 192 ar^ - 160 aj^ - 12 jb. 6. m® — 3m* + 5m^ — 3 m — 1. 7. 18 a* + 90 a^ + 125 - 3 a« - 31 a^ - 75 a + a\ 8. m3 + m2+^+ ^ 9. a« + ^V^^''^' a^ 3 27 4- a^ 10. a^-.^"'^ ■ ^^^' ^' 2c "*" 4c2 8c^ 11. a^-3a:5 + 2a^-a:3^2^_«_l.. 3 3 27 Extract the sixth root of : 12. 1 - 6 ?ri + 15 m2 - 20 m^ + 15 m< - 6 m« + m«. 13. a« + 60 a^62 ^240 a^b* + 64 6« - 12 a'b - 160 a^b^- 192 ab^ V. EVOLUTION— NUMERICAL Exercise 43 Find the square root of : 1. 3969. 5. 15129. 2. 6561. 6. 93636. 3. 8464. 7. 1772.41. 4. 10404. 8i 2672.89. 9. .986049. 10. .01449616. 11. .01018081. 12. .000104101209. INVOLUTION AND EVOLUTION 16 Find, to four decimal places, the square root of: 13. 8. 16. 2.5. 14. 14. 17. 37.561. 20. 1.0405. 15. 175. 18. .375, 21. .0035. 19. |. Find the cube root of : 22. 42875. 25. 12977875. 28. .001481544. 23. 250047. 26. 28652616. 29. 34328.125. 24. 1860867. 27. 74.618461. 30. 20.570824. Find, to two decimal places, the cube root of: 31. 9. 33. 7.3. 35. |. 32. 67. 34. 2J. 36. .0042. Find, to two decimal places, the value of : 37. V5. 38. Vi5. 39. ViO. 41. V^. 42. v:oo7. 43. VIl2. 44. a/IO. 45. V.0017. 46. V2V2. 47. V5 -f V3. 48. V5-f-V3. 49. ^10-fV7. 50. Vl5-3^i8: 51. 40. V.9. ^ 5 + V5 52. J 10+4V3 . ^ V2 53. V.038 4-V.009. 54. Vv:5+\/A 55. vio+Vio+^10. REVIEW Exercise 44 1. Find the H. C. F. of 5 a* - 4 a^ - 64 and a' + a^ - 20. 2. Take ic^+3 from a^ — 2.x^-^Xj and multiply the re- mainder by a; (a? + 3). 3. Find four terms of a^ -^ (a — 2). 4. Prove that (''+^)'-<"-^)' = a6. 4 5. Find the value of Va^ + 2/^ + 2;^ — (ic — 2/ — zy, when a; = 3, 2/ = — 3, and z = 0. 6. What is the remainder if (a — 2) (a — 3) (a- — a + 5) is divided by (a - l)(a + 2) ? 7. A certain divisor is a^ -{-x — 2 and the corresponding quotient is ay^ — x— 1. Find the corresponding dividend. 8. What quotient will result if the sum of x^ — 5x^ -{-Sx and 2qi^ — 5x — 1 is divided by the sum of 3 i»^ — 2 a; — 3 and -2i»2-h4? 9. Solve ^^-^ + ^-=^=2. x-\-2 X — 5 10. Prove that ("-fe?)^fe?)+(4ef)'=-- 76 REVIEW 77 11. If m= r, ^ = n^ P — a + 1' a + 2'^ a + 3 find the value of z hi h 1 — m 1 — n 1— i> 12. What value of x will make the expression 3(a; + 2)-4(a;-3) equal to twice the value of a; ? 13. If -Ti = 9, find the value of — ' Sa—x x—a 14. Show that 5a; -2a:-[4-i(a.- + 4)-21a;-3-(a; + 2)S-4]-^ = a 15. Show that a(h-\-c — a) h(c-\-a — h) c(a-{-b — c) _^ (a _ 6) (c - a) "•" (6 - c) (a - 6) "^ (c - a) (b - c) ~ ' a-{-4:b 2 46 — g .. .Q- r^ a-46 46 + a /2 IN 16. Simplify -^— X^--2^} 17 Ifg- 2findvalucof (^~^^^^~^^> (l+a)(l+2a) 17. It a- ^tmdvalueot jf^^^ (r=2^) 18. Solve ^-^^-1-^ + ^ + ^=0. 2g — a; a; + 2a 19. Simplify 6 («-!)(« -2) a — 1 a + l .O.Add4[^-l(ao-l)]a„<i3[^_l(c + l)-2]. 78 REVIEW 21. Solve — ; ; — = m-\-n. x-\-n x-\-m 22. Show that (a-\-b)(a+b-l)=a(a-'l)-\-2ab-\-h(b-l). 23. Find the value of — — a(x-^l) ^^ ^ IX X when X 24. If a = ^^^ and c=^^, findcwhen 6 = -l. 62 a 4- 3 26. Simplify a-lb-o-\2a-2,-U3o-m, a— J when a = 1, 5 = 2, c = 3. 4a; .4 3i» + l T 3 5x + 2 26. Solve ic- 5 2 10 11 a; + 6 27. What must be the value of m in order that 6a^- a^- 11 a^-lOa-m may be exactly divisible by 2 a^ — 3a — 1? 28. Show that ^(^-'^) _^JP±^^a when a = x-c. 29. Given that m = - r and ti = — - — -, 1 + a^ 1 + a^ prove that m^ + n^ = l. 30. Prove that — satisfies the equation 3 4a; — m x-^m __^ 2x — m x^m~ REVIEW 79 31. Solve (a;-f3)(2/-2) = (a;-5)(2/ + 4) + 16, {x — y){x + l) = l — x{y-x). 32. If x = ^^ and a = ^~^^ find x in terms of m. 33. Solve a(a — x) = b(x-^y — a), a(j/ — b — x) = b(y — b). 34. When x = 2, find the value of "-[-K''-^i)-|f-i)-<-8}-f]- 35. Solve (a-26)aj + a2 + 52 = (2a-&)a;-2a6. 36. What must be added to 2[l-3a;fl-2a;(l-5a;)j] to produce -5-3x{l-2xy? 37. li x = — ^^ and m = ^ T" , find value of a; in terms of n. w 2 ' 38. What must be the value of m in order that x = 2 may- be the solution of m{x — m)—S(x — S)? 39. Arrange (m — 2)* — (m — 1)^ + 3 (2 — m)^ in ascending powers of m. 40. Solve ^-^= ^ + ^. a; + 2?i a; — 2m 41. Expand [m- 3 n-f3(m-n) -n}]*. 42. Find the square root of (m - nyi(m -ny-2 (m^ + n^)] + 2 (m^ + n^. 43. Solve ^-:=i^ + ^-ii^ + ^:::i-^ = l + ? + ?. en cm mn m n c 80 REVIEW 44. What expression multiplied by itself will give tlie ex- pression 4^rc6_i2a^ + 5x'-hl4.a^-llx'-4:X-{-4.? 45. Expand (a^ — 8cy and extract square root of the result. 46. Divide 1 ^^„ by 1 — —^ — — and extract square (a-\-by -^ d'-ab + y' root of the quotient. 47. Simplify V(a-2c)«. 48. Show that the difference between the squares of any two consecutive numbers is 1 more than double the smaller number. ^ 49. Prove that q r is a perfect square. a a^ — a- 4- a 50. Compute ^0.4 -f- V.004 to three decimal places. 51. Find the cube root of [2 a - (a + l-(a-2))J. 52. If a; = ^L+1, find the value of a — 1 ^(x + 4:){x-2)-2(x - 4). 53. Simplify \VlO — V5 to two decimal places. -- oi a — 3a; b — 2x -, 54. Solve = 1. 64-a; a + x 55. Find the square root of (a^_4a;4-3)(a^-9)(a^ + 2a;-3) x^-^ex-{-9 56. Find, to two decimal places : ^ / "^ . A/ V150 57. Solve 15y — 14:X = — 4:xy', SOy — IS x = 17 ocy. EXPONENTS 81 EXPONENTS I. TRANSFORMATIONS Exercise 45 Express with fractional exponents : 1. 2. Va. <ra. 2V^. 5. 6. 7. 8. 9.' 10. 11. 12. 3 Va-". V4al 13. 14. 15. 16. ^27 a^. 3. ^/a6Vd*. 4. ^32a:^2/'V^ Express with radical signs: 17. aK 22. abK 27. ahl 32. 2 c^dl 18. aK 23. abc^. 28. (ab)l 33. a^^y. 19. aK 24. 3 abhi 29. 1 34. 2ahhK 20. «l 25. ahl 30. 3 c^d^. 35. 4 c^d-. 21. 5aK 26. ahK 31. 7cd\ 36. m » 5 a"6«. In the following, transfer to denominators all factors having negative exponents : 37. ab-\ 42. 3 a-^b-\ 47. 4 a ^x. 38. ah-'c-\ 43. a-'bc-\ 48. 3-^m. 39. 2 abc-\ 44. a'b-'c-K 49. 9-kd. 40. abh-\ 45. 2-'a-\ 50. - 2-^a-^bc 41. 1 a~\ 46. 3a'b-K 51. -|a-'6c. R. & 8. EX. IN ALG, - -6 82 52 53. — } EXPONENTS Write the following without denominators : a' b' 54. 2^. mn ^6 ^^' KG 2 mri 2k, c 66- !|- cd 57. 2« . 59. ^«" 60. 4.C 61. 3a-^ a-'x-i ^ „^. Express the following -vrith positive exponents : 62. 3a-\ _3_. 4VFJ 63. 2 am-*. ^ ^ «"' 64. a'^b-'c. 72 i^. 77 ^~'^~' 65. mn~^. 66. 2a-^6V^ 73. ^^=^- 78 67. om~^6"^c. 68. ab~^xy-\ tA, (xZ-^ 73. 2a6-^ Sm-^n 74. 1 75. 2-V 0-^6 2Va-2c- 79. 3 mn~- 4 a-icd-3 69. mn-V^^. ^_,^ ^^ ^-'ab' 70. a-^6-V\ ' a-^ SVa;"^ Find the numerical value of the following : 81. 4i. 85. 16^ 89. 125i 93. 4"^. 82. 9i 86. 27*. 90. (-27)i 94. 9~^. 83. 4l 87. 27*. 91. (-64)1 95. 16"^. 84. 9I 88. 8li 92. (-125)1 96. (-27)"i 97. 36"*. 98. (-32)-^. 99. -s/^^^. EXPONENTS 83 100. ^J/(=:27p. 109. Sl-i.l;. 117. -(-2i^)-l 101. (^=:27/. jj^ 2-3-2-- "^- ^*)'*- 102. ^K ,,,; ,6-i".8i "'■ ^-«^"*- 103. (^16)'. ^^^ gi. j__ 120. ar^-^(#. 104. (<^^/. ' 32*' 121. 3-^. A. 105. 2-^.3->. 113- 9-* -81*. ,-j „j 122 T 106. 3-2.2-2. 114. 2-2.32.4.6-1. • 27^ 107. 9-^.27*. 115. (2J)i 16-^ . 27"^ 108. 16^.8"*. 116. (l^^^)"^. * 9-^.64-* 124. (4-3 . 3-" . 23) -^ (16-^ . 27"* • Sl"^). Perform the indicated operations in the following : 125. w « . a-\ 130. (i-« • a». 135. m-^-m^. 126. 0/ ' . a-\ 131. a^.aK 136. 171^ -m^. 127. a .a-8. 132. a ' ai 137. a-*-i-a\ 128. a' ^ . a-2. 133. a-i . a-i 138. a-3-^a-2. 129. a- -' . a-^ 134. aKa-i. 139. a-^^al 140. a^cc . ax-\ 147. 8*4-9i 141. amhr^ . a^m" -V. 148. 8-^-9-i 142. 2a62.3a-i6- -1^ 149. a'h . a-162 . ah-\ 143. a« + 6«. 150. 2 a . 3 a^ . a-*. 144. 3a«-(3a)«. 151. 3 a^a^^/ • ohcx-\ 145. (a + &)«. 152. o?^fx • a^ic-^ 146. (-2)-3-(- -3)-^ 153. 2Va-3aV^-a;"^. 84 EXPONENTS 157. 168, 163. 164. 165. 166. 167. 168. x-Wx 154. a^Vx . a^Vx^ h- aV^. 155. 2a-^V^.3aiVx^^-ax-\ 156. x'^aVc^-^x-^a^Vcd^. 159, 160. VaV a^\a^Vx 161 162. 3a;-^ a^a; 'VacVac 3 m ^Vo^ mn- ^Vm^ Sx'^V^ ■ a~^^ax~^ xr^-y/a-^x 2aWx^' a'^y/d c'Voc^ 169. 170. 171. 172. 173. 174, oT^x-' 2aV9a^ 3 c-s/21 x--a-' 4 'V^TlV^ 12/- V4 a^x- Keduce to the simplest form : 175. {aj. 178. (a3)-2. 176. (a2)3. 179. (a-^f. 177. (a2)-i. 180. (2a'y. 3x^-s/-Ua-^x a/-27V64^ -^-125a-«' 181. (2a-3)-2. 182. (a-2)-^. 183. (4a-^i (a-^-i EX 198. ( PONENTS 212. 85 184. (S/-32c^«)-3. 185. (Sx^)-^ 199. ( 2-'a-^y. 213. '\/-81-*a«. 186. {x-'^)-\ 200. { ;8-^)^. 214. (9a-'y-r^. 187. (5aby. 201. ( ;-8-^)^ 215. (16a-V2/2)-l 188. (a'by. 202. ( ;- 27-^1 216. {aV^'y. 189. (a-'b-'y. 203. ( ;-i25)-^. 217. (a-'V^y. 190. (ab-r^ 204. ( ;-8a2)i 218. (a-WaV<)-^. 191. (a*b'c-^^. 205. ( '2a-'c^y. 219. (a-Va-^-l 192. (646c-2)-l 206. ( [2ah-'y)-\ 220. (2a'^V^'y'. 193. (-4a)l (-aby. (-2a'by. 207. ( 208. ( 209. < [2m^np-Y\ 221. 222. 223. (ab-Wa-'by^- 194. :^-sa-^y. (aV4a-^)-3. 195. [■y/16a'b')-^ (x-^yjxVwy. 196. {-2aby, 210. [2a-^Sa-y\ 224. l(Va-'by\\ 197. {-^a)-\ 211. [8a-2c-3)-l 225. l(^Sa*by\\ 226. ' l{</27'a-'yy\ 227. yjie-'x^^. 228. (^[m^)^. 3/ ; 229. y-SVaF^. 230. (yjVu^y. 234. [(64ar^.^]- 235. ^j(16x'y-'Vxy)-^ 236. VV^Vm -\/- mx ' m 231. (a-'yJ27arix^)-\ 232. l^[(^</^Wr'f. 233. (^125 a^V^-^ 237. (V27^)-2-- (V9¥-3)-i. 238. \m~^n^^mn~^yln^) ' ^6 EXPONENTS 240. y25a-^bVx-''-r-y9a-'b-^Vs^, 3 242. 243. 244. 245. \xl^^^'\\^^^\~\ 246. ^ M^;y6 c-3^g^y i^ Vc-' Vad- 1^-^ 247. \\l- V". J27«V^|-'. .48. [^^"^^-.g^^^J 249. (V •^^"'^'_ . ^332^i^F^r'. I ^25a36-i^c2 J 252. iVa^ft-W^'c-iaVcVWaSc) EXPONENTS 87 Collect; 253. (|)i+(^V)i + (32)i 254. (2)-2 4.8^-4-\ 255. 3-2-27-^4-9"^. 256. (^?yVl6-f + A+(_2)-». 257. (3)-i_ 2-3 + (1^)^ + 128-1 258. 9-^ + 13 a;*' + 1"^ + {^)-\ 259. ■^2TF'5_:^ + J-_128-*. 2"^ 8"^ 260. 7aJ»-(7a;)«-17^ + A. 2 261. 8i-*-A- + :^-# 27-^ V34 9-^ Simplify : 262. 2". 22-^2". 271. (a^+i) V*)' ' («'"0~^- 263. 4 "-2 . 82-" . 2». m _n n 264. (4-. 2-) ^8. '^'- (-'^'^O-. 265. (af^-^-^i . (a^-r . ar=. 273. (3^+2 _^ 3 • S'*) ^ (9 • 3"+^. 266. {ahy+y -^ a'fb". 274. (a^^-^^ • a;-^«-*) -^ a;"'*-^. 267. a'"+" . a^"*-" • a""^. 275. S[(a)'»-i]-'-i ;""•+». 276. [K«^-r^r]-[K^m- 268. ar^^a^"*. 269. [(a'=+^)^-^ -5- (a^-*)^. 270. (x"'-^y(xP-''y(oif-^y. 277. (Va'^^-j-Va)'^^^^ EXPONENTS 278 279 2n+iy2 . 2"-3 1 "*^ 1 280. KC'""'0'"{ m2-l.^„»+l^ 3n a+6 g— 6 2a 1 283. ([ic *= ] . [ic~] -h a;~^)^ 284 -. [^'{5)•(')(S)r■ II. MISCELLANEOUS APPLICATIOJSTS OF EXPONENTS Exercise 46 Multiply : 1. a-2 - 2 a-^b-^ + &~' by a^ - b-\ 2. a^ + aM4-2>^ by a^-{-b\ 3. a-2-2a-^ + 3-a by 3a-^-2-2a. 4. a^ — aM + 6^ by a^ + ah^ + b\ 5. a-3-2a-2 + 3a-i + l by a-2-3a-i-l. 6. 3a^-6a^ + 4 by a^ + 2aJ-3. 7. sJ-a^-{-2-4.ar^ hy '2a^-S + 2ari 8. ^-f.l^_-^ + 2-^by ^-2 + ^'. V^ Va; Va; Va Va; Va EXPONENTS %% Multiply the following by inspection : ' 9. [a-' + iy. 18. (a-2-3)(a-2 + 2). 10. :a- + 3)l 19. (a^+4)(a^-h5). 11. [a-^-4.y. 20. (5-«-2)(3 + a-^. 12. ( [a-' + h-y. 21. (a^ - 6^)(a^ 4- 6^). 13. [a^ + b-')\ 22. (a-^-3)(a-^-2). 14. [a-^ + h){a- ^-h). 23. (a-^_a-i)(a-^-2a-^). 15. ^a-^ + 3)(a- ^-3). 24. (a-^6 + c-i)(2a-i6-c-') 16. ;a-2-4)(a- -2-1). 25. (a-i + 6-^ + 1)2. 17. :a^-2)(ai + 2). 26. (a-2 + 6-2_c)2. Divide : 27. a-3 + 3a-2 + 3a-^ + l by a-^ + l. 28. a"^4-2a"^ + l by a"* 4- 1. 29. a + 6 by a^ H- &^. 30. a— 125 c"^ by a^ — 5c"i 31. a*-6a^ + 12a^-8 by a^-2, 32. x^-\-a~^ by a;^4-«~^. 33. a'— 3a^ + 3a"^-a"^ by a^ — cC^. 34. 10x-''-27a;-3 4-34a;-2_18a;-i-8 by ^x'"" -Qx'^ -2. 35 . 12 a"^ - 17 a"^ - 9 -f 13 a^ - 63 aHy 4 a"^ - 3 + 7 al 36. 6 a~i + 11 a ^ V » = -^-z + 10 ic^ by Va Va — + 5 a-^a;^ - 2 a;l 90 EXPONENTS Divide the following by inspection : 37. (a-2 - 9) by (a-^ + 3). 42. (a - 8) by (a^ - 2). 38. (ci-2-6-2) by (a-i-6-i). 43. {a^ + 27) by {a^ + 3). 39. (a--* - 16) by (a-^ -f 4). 44. (a-^ - 64) by {a^ - 4). 40. (a - 81) by (a^ - 9). 45. (a"* - fe-*) by (a-^ - ft-^). 41. (a-'-b-^)hj (a-^-b-^). 46. (a--* - 16) by (a-^ - 2). Factor : 47. a-2-6-2. 57. aj-* - 9 a;-^ + 8. 48. a-^-81. 58. x-^-Sx-'^-ASx'K 49. 4a-2_256-^ 69. 2 x'^ -{- x-^ - 10. 50. a^-9. 60. 4a;"^ + lla;'^-3. 51. a^-8. 61. a;^-27. 52. a-2 + 5a-^ + 6. 62. a;^ + 64. 53. a-2— 6 (1-^-^ + 5 2/-^ 63. a;^ - 8. 54. a^ — lOa^ + 25. 64. a; — 4. 55. a^ + 8a^.4-16. 65. Sa?-\-b\ 56. m"^-5m"^-36. 66. a-i + 1256-'. Simplify : 67. a-'^b-\ ^4 (a + l)(a-l)-i4-l 68. a-' + b-\ ' (a -\-l) (a -!)-'-! 69. a-'b + ab-\ 75. ^-(g + ^)"\ l + (c_l)-i 70. a-^bc + ab-^c + abc-\ 71. a-\a + b) + (a^b)b-\ 76. ____^--^_^. 72. (a;-l+rO-^(a5-^-rO• ^^ a(a _ l)-i 4. 6(a + l)-i 73. (l+mn-i)-7-(l+m-^w). ' a(a+ 1)-^ + 6(a-l)-i* EXPONENTS 91 78 mn-^ + nr^n ^^ x(l -[- a;)-^ + x-\l — x) m~^ — m~^n~^ + n~^ ' x(l + a;)~^ — a;"^(l — a;) 80. r a-| + (m + n)-n |-j^ _^ ^^2 ^ ^2 _ a')2-'m-'n-'l 81. [(m + a)~\m — c)~^ + (m — a)-^(m + c)"^] -s- [(m + a)"\m + c)~^ + (m — a)-\m — c)-^]. Expand : 82. (x-2x-y. 87. (V^-3V^)*. 83. (2a;-i + 3)^ 84. (x-^-Sa^*. 88. 85. (a.-f2a.-0^ ^^ ^__^ ^^. 86. (Va;-A/a;)3. Extract the square root of : 90. x'^ -10 x-^-\- 25. 91. a;-8a;* + 18ic^-8a;i + l. 92. 9a-2-6a-i + 13-4a + 4a2. 93. 9a;-*-30a;-3 + 67fl;-2-70aj-i4-49. 94. 4a;^ — 4a;^+13iB^-6a;^ + 9. 95. 9(B-12a;^ + 34a;~^-20a;~* + 25a;-l 96. 16a;-^--^7^-7 + 12^/aJ + 4^/a^. ■y/x ^^ 9 a 24Va 24 V6 , 9 6 , ^^ 97. -7 ;= ;^H l-o4. ^ V6 Va « 92 I EXPONENTS Solve the following equations : 98. a;-i = 2. 105. a;~^ = -8. 112. X~n = — 2. 99. ic^ = 3. 106. xi=^. 113. --* = A. 100. x^ = -2. 107. a;"^=-i.. 114. »="* = t1t- 101. x-^ = 2. 108. x~^ = l. 115. 1 102. a;~^ = — 3. 109. a;"^ = 16. 116. V5="^=iooo 103. a?* = 8. 110. a;" = 2. 117. x^ = </K 104. a;^ = -27. 111. a;" = 2*". 118. xt = V^. 119. (a; 4-1)' = 4. 127. (a^ -l)-2 = i- 120. (a; + 2)3 = 125. 128. (2 0.-1)- •'=.v 121. (a;-l)^= = 3. 129. (X- -^ + 1)- '' = 9. 122. (a? -5)^ = = 1. 130. (X ■^ + 2)- ■^=16. 123. (a; + l)^ = :4. 131. (a.- ■t-5)- -^ = i. 124. (a;-3)i= z8. 132. (a:- ■^-i)- ■'=h 125. (a; + 4)-3: = 27. 133. (X- -^ + 3)- -" = 1. 126. (3aj-l)- 2_ :i 134. (X ■|_7y = 1. Find the value of X in the following : 135. 4* = 8. 138. 9^ = 27. 141. 8' = ^T. 136. 4* = 64. 139. 9^ = ^V 142. 32- = 9. 137. 16^ = 8. 140. 27* = 3. 143. a)-^=8. Find the value of x in the following : 144. x-^ = y', y^ = 4:. 148. 145. x-^=y', 2/^ = 2. 149. -^ = -8. 150. -"> 151. 146. x'^ = y-^', 147. 3.-1 =2/* J 2/~^ = -2. «"^ = y-^ ; 2/f = 4. a;"^ = y~^ ; t/ = '^' BABICALS 93 Find the value of n in the following ; 152. 2«-i = 16. 157. 3"+! = ^. 153. 3'*-i = 27. 158. 4'*-2 = J[^. 154. 9"-^ = 27. 159. (i)'*-' = ^. 155. 4"+' = 16. 160. (i)"-' = A- 156. 16~-^ = 8. 161. (1)"-' = ]^. RADICALS I. TRANSFORMATIONS lizercise 47 Reduce to the simplest form : 1. V8. 14. --v/128. 2. Vl2. 15. -v^^Si. 3. V20. 16. \/32. 4. V28. 17. -^162. 5. V27. 18. --^96. 6. V45. 7. V48. 20. Vo^. 8. V72. 21. VaFb\ 9. -Vl25. 22. Va^¥?. 10. ^16. 23. -Vl8^. 11. ^24. 24. V27V- 12. -a/54. 25. ^54^i¥. 27. 28. -■v/320a%V. 3 V27 a. 29. 4V28a«6^ 30. 2 V56 m%3^ 31. V20 m^*. 32. -2-v/250a* 33. ^16 a^^«2/^«. 34. 35. 36. 3-V/64 m^n. i V54 a^ 37. -^V20 6c^c?. 38. -v/54 ai«6^. 13. V108. 26. -V128mV. 39. -\Vi25<^', 94 RADICALS 40. i/27a''3^. 41. aV(a + c)^ 42. -aV3a\a-{-iy. 43. 5mV(a-l)l 44. -a^a%a-iy. 45. Va« + 2a2a;_{_aa;2^ 46. V36(a2-»^)(a + x). 128a^ 9c2 48 ■V 49. m^ 50. aV 25 ar^ 3^ 108^ 49 c^ 63 64. 65. Change to entire surds : 51. 2V5. 54. 2^/5. 52. 3V7. 53. 4V3. 2 3/9^2 a' a /- 3 /o- — V2a. m Keduce : 73. Vi 74. V|. 75. Vi. 76. VS. 77. V|. 78. V|. 55. 3^4. 56. 2^7. 66. 67. 3a 2 57. 2aVa. 58. 8a-Va. 60. 3a2^a2 61. 2a-\/3aP. 59. -2a Va. 62. -2aV5a. "2^. 69. -^'^9. 2_a3/_3_ 3\2a 68. -^V^l 70. 71 72. -(«-l)^5?I• 79. V|. 80. Vf. 81. Vf. 82.4 'a? 83. Vf- 84. ^. 85. -^J. 86 87. - a4-2> a + & 3 3/ n~ 88. 89. 90. 2Ai^. BADICALS 95 91. -3^^. 4: ax 27 * 92. i^ 93. 95. 96. _9_ /4_ac 2a^' 3 ' 99 A/l2a2 « 3 aV 3\^- 94. -AJ/-^ 3a ^ 8 Simplify the indices of : 2c^ 8 1 27 a* 3a\ c2 * 97. iV^. 100. V6|(m-n)^ 101. -y/^ia+iy. 4/ 9" 103 104. -Vc^. 105. a/9. 106. -v^. 107. -^^25"^^. 108. ^?d^V^. 102. VW^^^^ 109. -v^QoV^. 110. -^/Sl aVd". 112. V27aV2. Change to radicals having 114. V3 and a/5. 115. V5 and -y/W. 116. a/9 and -s/l, 117. Vl5 and -v/SO. 122. Vm, Which is the greater : 123. 2V3 or 3V2? 124. Vil or -\/30? 125. 2V3 or a/42? Which is the greatest : 129. V5, a/10, or a/IS? 111. Vl6a*b'c\ 113. a/100. the same index : 118. Vn and A^SO. 119. a/25 and a/75. 120. a/6, a/15, and a/35. 121. A^, a/7, and a/10, a/w?, and a/wi^. 126. 3a/5 or SVS? 127. 2a/4 or a/10? 128. a/| or a/|? 130. V6, \/16, or a/35? 96 RADICALS Collect : 131. V50H-V18-V8-V32. 132. Vl8~V98+V50-V72. 133. V27-VI2+V75+V3. 134. Vl2a-V27a-V48a + Vl08a'. 135. Vow^ — Va%i + VOom^ + V4 a^m. 136. |Vl2-V50 + ^V48-Vi8. 137. V20-V| + V| + 4V2-3V5. 138. Vl24-Vi-V27 4-V|-Vl08. 139. V50-^-6Vi + 3V|. 140. -^i-Vi + V98-2V27. 141. 2-v/| 4- 3-5^ -2^/144. 142. 2V|-3VS-V}4-Vi000. 143. 3Vo^ + 4 25 4/aV 81 144. V50-v''432+V32 + ^250. 145. 3^4-^24-^3+A/i6. 146. 30VJ-fV8 + 9V84l. 147. VT80-2V5 + 15V|. 148. |Vl62 + 10V4|-13V2. 149. -t/36-V|-4V6 + 2VJ. 150. 10Vl2} + 7V2-3V338 4-5^ + 4Vf. 151. V24-6Vi + iV96-V66| + |V¥- RADICALS 97 152. 6V33j-V96 + V|-|V-^ + 4V6. 153. 12Vi6j + 5V3-5V432 + 6V^. Multiply : 154. (V20-fV80+V45) by V5. 155. (V8-2VI2 + V2O) by V6. 156. (^-1^32 + -J/5) by ^/16. 157. (2V3-2)(2V3 + 2). 158. (2V5 + 3V2)(3V5-4V2). 159. (5V3-2V2)(3V3 + 4V2). 160. (V2+V3)2. 163. (3V2-5V3)2. 161. (V3-2V2)2. 164. (V3-V2)^ 162. (2V3-2V2)2. 165. (2V2-2)^ 166. (3V2-2V3)3. 167. (V7-V2 4-V5)(V7+V2-V5). 168. (3V| + 3Vi-10Vi)(iV24 + iV75 + V20). 169. ( VlO 4- Vl9) ( VlO - Vl9). 170. (Vl3 - 2 V22) (Vl3 4- 2V22). 171. ( V2 -\-x-{-Vx) (V2Tx). 172. ( Va + 1 - 2)2. 173. (2 Va^"^^ - 3)2. 174. ( Vm + 1 - Vm - 1) ( Vm^^). 175. ( Vm + 2 -f- Vm) ( VmT2 - 2 Vm). R. & S. EX. IN ALG. — 7 98 RADICALS 176. (m2 + mV3 + 3)(mV3-3). 177. (Vm — Vm — n + Vn) (Vm + Vm — n + Vw). 178. (Va-l+Va + 1)-. 179. ( V2I - 6 V3) ( V2I + 6 V3). 180. (5V?T^-4V?^^2. 181. (2V^ + V4^^)(2v^-V4"=^). 182. (Vo+I - V2)(2VaTl + V2)(2a+ V2a + 2). 183. VS--\^-W- 185. Vi|--v/W- 184. VS--\^||- 186. (V2-2^/4)(2V2-^/4). Divide : 187. 2V32 by 3Vi20. 193. \V^ by ^V^. 188. \/8l by V3. 194. (5V18-3V27) by 3V5. 189. ^J/12 by 4V2. 195. (2V54+iV24) by 3Vi. 190. VU by ^32. 196. Kk by Ajji. 5 Vc "^ 10\a 191. -Wc^ by -ySom^. r- 192. (^12 + 4VI8) by 6V2. '''• (IV^-^V^ ^^ ^• 198. (12V5 - 8V15 + 3 V30) by 6VIO. 199. 10V3 - 15V42 - 9 V2 by 5 V6. 200. (5^^^ 4- 3^/45 + 6^/30) by 2\/i8. 201. (</32--v^'48-a/80) by </3 202. Xi^, by f-^^j:K:Y RADICALS 99 n. MISCELLANEOUS APPLICATIONS OF RADICALS Exercise 48 Extract the square root of : 1. 6 + 4V2. 7. 44-16V7. 13. 16 + 2V39. 2. 11 + 6V2. 8. 30-12 V6. 14. 74-6V77. 3. 28-10V3. 9. 88-16VI0. 15. 77-28V7. 4. 21 + 8 Vs. 10. 57-f-12Vl5. 16. o?+h + 2a^h. 5. 45-20V5. 11. 207-40Vli. 17. o? + 2c^-2a^/2~c. 6. 42 + 12 V6. 12. 82 + 12 V42. 18. m"^ -\- m + 2 m^Vm. 19. 2a; + 2V^^^. 20. m^H- (2m-2)V2m-l. Rationalize the denominators of : ,1. A.. 29. -1-. 37. 2Va + 3Vc- V2 V3-2 2Va-3Vc 22. A. 30. -^ 38. 5V2^-V6j. V3 V2+V3 5V2a; + V6a; 23. A,. 31. 2 + V3 g^ 4V2^-3V^ , V2 * 2-V3 * 3V2^ + 5V» 24. 11. 32. ?V|±2 ^^ aVc-ftV^ , ' V6 * 2V2-1 * aVc + 6Va; V24 ^, V5-V3 a + V^^^=^ 25. -^^-^^- 33. 41. V3 V54-V3 * a-^d'-l 26. ?^. 34. ^^ + ^^ 42. V^-3+V^ . Vi2 * Va-V6 * VaJ-3-V^ 27. -^. 36. 2V3 + 3V2. ^3 2+V2 2V3-3V2 28. ^. 36. 3^-2^^. 44. V3^ ; + l+V2a- -1 V3^ ' + 1- -V2a- -1 Vm^ -2- -Vm2 + 2 3-V3 2V5-2Ve Vm2-2 + Vm=^-f-2 100 RADICALS Find, to three decimals, the numerical value of: 45. ~ 47. -^. 49. V3 2V3 2^2 46. A. 48. A. 50. ^^^±1. V5 -v/2 V2-1 53. ?V|±3^|. ^^^ 51. V3 + 1 V3-1 ^9. V3 4-V2 V3-V2 5V3 4- ■2a/2 2v3-2V2 V2-V3 Simplify : 55. Vl5-6V6. V8 (V6-V2)(V3 + 1) 58 Va; + 2 + Va^-2 59. Va; + 2-V«-2 1 . 1 a — Va^ — 4 a 4- V a^ — 4 60. ^ _ + 1 (3-V2)2 (3+V2y g^ 2V^-i ^ 3V^"=i: 3Va; + l-2Va;-l ^^x + l+2Vx^^ ^^ V26 4-8V3 _ V6- V2 63. :^^19-8V3, V3 + 4 KADICALS 101 64. 65. 66. 67. 68 Va 4- V^ Va — Vb 2-Vb 2Va V3-I-V2-V2 V3 + V2 + V2 a; + 5 ic — 5 ( Vll + 6V2) + (^6 + 4 V2) ^ 5 - 2 V2 \ ^ a* a ^ a; ay 70. [3V3+(V28-16V3)]2. 71. 72. 73. 74. (a; + V4-^(a;-V4-arO V34-2V2-V3-2V2 V3 + 2V2+V3-2V2 3-V2 Vo; 4- 1 + Va.' — 1 Va; + 1 1 Va;-1 34-V2 V3+V3+V2 V3-V3+V2 a + Va r a-4 (a4-2)Va "| « (« + 2) LVa - 2 a H- Va J [Hint: a - 4 =( Va + 2)(V^ - 2).] 75. 102 RALICALS 76. Show that — - — = 2 + V2. 2-V2 77. Show that ^ + ^^~^^ =V5-2V6. 2_V2 + V6 78. Show that ( V24 + 16 V2 - Vll + 6^/2)^ = 5.82842 +. 79. If a; = 4 + 3 V5 and 2/ = 5 + 2 V5, find value of (a^ _ /)2. Solve: 80. V^+T = Vl2. 85. 2(V^-3)(V^ + 3)=3. 81. V«T3=V2a;-10. 86. Vx^^ - V^^^ = V2. 82. 3Va;-9 = 2Va; + ll. 87. Va; + 3 + Vx- 2 = 5. 83. 2V^T3 = 3VlO-a;. 88. V3H-V9i» + 1 = 3V^. 84. VflJ 4- 13 = 13 — V^. 89. Va; + 9 mw = 3 m + V^. 90. </10a;-6=V2. 91. Va; + 3+V9aj-l=V4a;-l. 92. V2a; + l-V8a;-l=V2a;-l. 93. ^j7 + ^^S + ■^^ = 3. 95. ViC + 7+V^ = ^. 94 V^ + 3 _ V^-f-9 __^__ V^-2 V^ + l" 96. V2+V^^^ = V^^^. 97. — Va; — 3 = V^. Va;-3 98. V^ + V^"^ -5__ = 0. 99. 2a^ = ^ 4-V4a;-3. V4a;-3 IM AGIN ABIES 103 100. V^^^ + V^ = _6. Vx — 5 — Vic • VaJ + m — V^ _ 1 Va; + m + Va; ^* 102. 103. V2a;-a2-f-V2a; + a2 = 26. 104. Va;-2a= ^^ - V^. Va; — 2 a 105. V2^ — Vm = V2a; — Vm(5m + 8a;). 106. J^- J^ = 0. 107. a; + 4 ^a; — 4 3VS + 2 3V^+1 2V^'-7 2V^-5 108. 2-\/x - 2 - 3 Va; + 2 = 5 V^. 109 Va , « /- Simplify : IMAGINARIES Exercise 49 1. V^=^. 5. 2V-81. 9. -2V-36a«. 2. V^16. 6. V=^. ^^- V-(aj + 2/)l 4. V^lii. 8. -V^9^^. ''• -^^-(" + ")^- 104 IM AGIN ARIES Collect: 13. V 14. V 4 + V-94-V' "9 4-V^^^36 25. V-49+a/^64. 15. V^^36 + V^=32r-V^^100-V^169. 16. 2V-9 17. 3V^=^-V 3 V^^16 + V-49 - V- 25. V^^144+V^256. 81 18. iV 4 H- 2 V- 36 - \-\/- 25 + iV^^ST 19. 2V^ + 3V^ v 2V- ^ + 3V-^V 20 + 2V-4a2-V-9a2 + V-16a2. 21. V-4m2-iV-16m2-h2V_i21m'^-V^ m'' 22. aV Multiply : 2 a 16 a^ 23. V^^ by V^T. 24. V^=^ by V^^. 25. V^^ by V3. 26. 2V^^ by V^^. 27. 3V^^ by V^^. 28. V^^ by 2^^^. 29. 3V^^ by 3V2. 30. _ 2 V^=^ by V5. 31. 2V^^ by -V6. 32. 3V^=^ by 2V^^. 33. 3V-27 by -V^^. 34. - 2 V5 by 3 V^=^. 35. a^—a by Va. 36. — aV— a by — V— a. 37. -2V-3a by 3V^^. 38. — 3aV— a by 5V— a^ 39 40 — 2aV— 2(1 by aV277. -3aV"=^by -2aV^=^. 41. V^^ by V^6 by 2V^=^. 42. V^=^ - V^^n^ + 2 V^^15 by 2 V^^. 43. (3+V^ by (3-V^^). IMAGINAEIE8 105 44. (o-V^(5+V^. 45. (2-V3)(2-V^. 46. (2+V^(2 + 2V^^). 47. (5-2V^^)(3-3V^=n[). 48. (3V2-V"^^)(2V2-3V^2). 49. (4-3V^=^)(2+V^^). 50. (Vir3_v^(V^^+V^^). 51. (2V^5-3V^(3V^=^ + 2V=^). 52. (3V^=^ + 2V2)(4V^:^-3V2). 53. (3-V^)^ 54. (2-3 V^'. 55. (2V3-2V^' 56. (a-l-V^l)(a-l+V^. 57. (a + &\/^l)(a-6\A=3). 58. (2 a + 2 6 V^^) (2 a - 2 h^^l). 59. (V^l+V^2-|-V^^)(V^=i:4-V^=^-V=^). 60. (V^^-V^=^ + V=T)(V^=^+V^^-V^. 61. 62. 63. Rationalize the denominators of 3 12 V^=:3' 64. 65. 66. V-15 2V3 3V^=^ 2V^ 67. 3V-9 -6V-3 68. Vio V-2 RClk Vl5 2V-3 70. 71. 72. -5V12 Va 73. 1-V=2 74. 34-V-2 75. V2-Vi:3, V2+V"^ 106 IMAGINABIES 76. 77. 78. V3 4-V^2 1-V^ * vCis + v^ 79. 80. g + V-l . a-V^l* m + nV— 1 82. 83. m — n- 2a-|-6V^ 3a-26V^^ 2a-6V^ri 2-3V2 e, V2a+2V-2a ^^ a-vT=^ ol. ^ — — — — • o4i 2V-2H-3V2 Va— V— a a — Va — 1 Simplify : 85. (V^l)*. 87. (V^*. 89. (V^)-*. 86. (-V"=3)^ 88. (-V^=^/. 90. (-V^^)-^ 91. (1_V^'-(1-V^^)^ 92. (3-V^'-4(5-V^^)'. 93. (l+V^'-Cl-V^'^. 94. (1-V^^ 95. (1_V^^-(1-V^^+(1-V=^). 96. 2(V^n:)3-2V^(V^=3-l)^ 97. = (l--\/^^y. 99 V2-1 ^ 98. (1 + V^)--(1-V^1)-. 100. 2V^1 iC+V — 1 iC— V— 1 m + ^V— 1 , m — nV— 1 Find the square root of : 101. 2-4V^^. 102. 1-56V^^. Kesolve into imaginary factors : 105. a + b. 107. a + 2 6. 106. a + 4. 108. a2 + 4. m -- 71 V— 1 wi + n V— T 103. 32-32V^. 104. -3-12V^^. 109. a^ + 1. 110. 2«2 4.3. GENERAL REVIEW Iizerciae 50 1. 3. Find H. C. F. and L. C. M. of : J m^ + 6 m" 4- 5 m — 12, [m^-3m^-22m-12. 5. 6m3-llm2-14mH-24, 8m» + 18m2-llm-30. lOa^ + a^-hlSa'-S, 16a^-a'-\-2. l-8a;-3, l + 9x-^-22ar*, 4. rioa^ l8a^H-4a*^-2a2»_l. 1 3 a-1 - 4a~* - 13 + 14a^, Simplify : 2 mn(m -^ n)~^ — m . 2 mn(m -\- n)~" — n n-^ -\- (m — 2 ny^ m^^ -{- (n — 2 m)-^ i-1 9. (g - 1) [3 g + (<^ - l)n-^-(l-3 a-{.a^(a^^l)-^-(a-l)-\ (I_2g + g2-2a«)(l + 2g + :^g2 + a3)-i 10. [(m — n)(m + w)-^ — (m + 7i)(m — n)-^] 11. 1+ K, -W-2). 2- 1 + 1 2 + 3-2a? a;-l 12. If - = ±, show that n y n y 107 1^ 'T- GENEBAL REVIEW 1 1 ^-^^ + 1^-^ 14. (a-l)(a + 3)-i-l-(a-2)(a-3)-i + [5(3-2a)-a2][9^a2]-^ 15. m^-f 7M' m2 + ^/i"" ??i^ + m^ mr 16. [a-6(c-a-i)-i]-\ 17. If « = ^, show that '^^ + ^ = _3m±^. 6 n 6a-f-36 5m + 3n 18. Show that a^ — 2/^ ' (c — 1 Solve : 1 + 19. 3ic4-l x-\-^ x-1 ir + 4 1 + xy ix-yf 2a^ + a;-3 x-2x' + Q 2-^x^o? 20 3a;-l a; + l , ^a; + 4 ^ 4a; + 5 8 9a;-16 4 6 21. ^±l-f.(a;-l)(a;-2)-i ^^~^ cc + 2 x-1 6 23. 5a; = .-[3-{ aJ + a;-3 15 * 2 (7 a; -12)-^ [_' [ ' (3-a;)-M_ 24. [l+a;(l-a;)-i][l-a;(l4-a;)-'][l-a;'+(l-a;'K^]=3. 25. Show that -^ satisfies «-4a; _ a + 2x ^^ 5 2a — a; x + 2a GENERAL REVIEW 109 26. Solve (m + x){n-\-x)~m{n-{-p) = '^^ + oi:^. X ex 27. Show that cd + -, = — + « when x = ad. d a Solve the following 28. 29. 30. < 31. = 3, 32. x-5 2x-y-l _2y-2 4 3 5 ' 2y-^x — l _x-\-y 9 4 * x — 2 x-\- y—1 _ 3 4 X -\-S x — 2y—l _^ 4 2 2a; + l 2-Sy ^l 3 5 6' 3y-2 2a; + 3 _3 4 6 8* ( 4:X — Sy±l __x-\-Sy I 2^ T"' 3a; + 2y j^^ 2a;-3y 5 3 I ^x-V±y _ 2 x + 1. 3 ^ 2 ' 14 ^ ^^ 2 36- -I 37. 38. 39. f^ i_^_13 2a;"^32^ 3* 13a; 2y 27* ?/ a; 3a 1+1=A. x y 2a Sx-{-4:y — 5z = 2, 2x-Sy-Sz = -9, Sx-y-2z = 0. (2x-y-\-Sz = -i, 40. -! Sx-3y-2z = ^, \4.x + 2y-5z = 5i. ( cy + bz = 2, ^^ (ax-by = a^-b^-2ab, ^^ I ^,_^,^^2, 33. 2aj + 32/ = 3a; — 22/ = l. 35. i bx -\- ay = 2 ab -\- a^ — W. a-^b a — b 4a6 bx + ay = 2. [ x-'-y-'-z-' = S, I y-^-x- 110 GENERAL REVIEW Expand : 43. {2x-ay. 44. [3a - {2a+ (5a-2^"=l)i]^ 45. ( "^-^^ Y. 47 ^..--^^Y 46. {a-^ + 2x-y. 48. ("v^ ^-Y- Find the square root of: 49. a;-'^ + 4a;-3'»-2.'B-2'»-12a;-~-f-9. 50. a^-2a2»'-ll + 12a-2- + 36a-^. 51. 4-4a^-lla + 14a^ + 5a2_i2a^^.4aS. 52. (a;-2 - 4) {x-^ - 3 a;-* + 2) (a;-^ + a;"^ - 2). 53. (m + m-y-4(m-m-i). Find the numerical value of: 54. V.073 to 5 decimal places. 55. V.0073 to 5 decimal places. 56. Vs - 3 VXiM to 3 decimal pla<;es. 57. V.007 + .3 VlAi to 3 decimal places. Simplify : 58. ^!i^\^/:r2iw. 59. [-3-v/-27a-2-^(- 8-')-i]-'. 64. f-s/-S(^d- 65. 64-^-flV'</Sr^^ GENERAL REVIEW 111 67. (SaV^-h27 x^Vcir^yi \ 16 ac'VdJ 68. (a?"*)"-^ . (a^)'»+l(a;'")l-2^ r n+l _ _ 69. Jinh^.x^Va'n 66. (m^) « (m^) ^ -- (m-y\ \^ '^^ \ A^-v/n' 70. V25 a-ift V^(27-ia"V^^aa;^6-i)i 71. [7a;-V^]« • [3a^2/"*2;]-^ "^(s^^^T* Collect: "■ (1)^3^ 73. 7-1 + C^y - (7 a;)« - 49"^ - 2-2. 74. 81-^-5a;« + 9(3)-3+(125-V^ + rt 75. (^:^J_V3T27^ + (-243)i + (:^J- Multiply : 76. i-l + ft'^by a-2 + l+r^- 77. a3-3 + 3a-3-a-« by a'---^--- a a* 78. J^_4aj-i + ^-24by ^+4^ + 5. Divide : 79. a-^—b by a"*— &i 80. 27 m-3 - 8 w2 by 3 m-i - 2 nf 81. a;^+2a;^-16a;"^--32a;-^ by a;*+4a;'^+4a;"^. 82. a--^ + a-2'"62n _|_ 54n by 1 _^_j_?,2n 112 GENERAL REVIEW Simplify: 83. (oT + 2 a'^^y - {a'^ — 2 a-'^f. 84. [(a + 6)^ + (a-6)^]2. 85. [(7/i-l)*+(m + l)^J. 3x _35 86. (m'^-m ^)-^(m' -^l-[.m-''). Collect: 87. f VlGj + ^ - yV V432 + ^ VIp. 88. 5V75--jVi47--^ + 2VJ-^81. 89. Multiply ^ by -^^ by V|. Simplify: 90. (3V6-2V3 + 5V2)2. 91. (2V5-3V3-2V2)(2V3+V5-3V2). 92. (^9-6V| + V48)2. 94. (V3-V2)2-2(2-V6)(2-V2). 95. (3V2-V3)(2V2 + V3)(3V3-V2). 96. (?^-5^ + iO.V^25-^216). VVlO V6 V2/ ^ 97. V52-6V35. 98. V2a + l-2Va2 + a. 99. (^/2-V5)^. 102. (V2 + ^3--^)2. 100. (V2-^y. 3^-4^81 101. (2V2- 3^2)2. ^^^- -^243 GENERAL REVIEW 113 Kationalize the denominators of the following : 104. -^ -• 106. 3V6-2V3 ' V3-V2 + 1 105. — ^- -. • 107. '^ + "^ - Find the numerical value of: ^ V5 + V2 V2 110. Which is the greater, V5 or -^/\l 9 111. Which is the greatest, V|> \/f, or \/|? 112. Show that V| > ^f . Simplify : 115. If m = i ( Vc + d + Vc - 2 d) and yi = ^ ( Vc+c? - Vc-2d), find the value of m^ + n\ 116. Simplify by inspection : (Vm 4- 71 H- Vm — Vn) (Vm + ti — Vm — V^). 117. Change^— J^i-II-^ to an entire surd. c — cZ ^ c -f fZ 118. If a = 11, 6 = — 12, and c = 3, what is the numerical value of , /-To A — — 0— Vo^ — 4ac ^ 2a 119. If 71 = 11, a"=5V2-2V3, d = -(V2+V3), find value of ^[2a + (7i-l)d]. R. & S. EX. IN ALG. — 8 114 GENERAL REVIEW Simplify : ■« X — 1 x + 1 Vx — Vy -y^ + V^ 122. 123, f^^^ — h — Va + & Va — 6 -f Vg -|- 5 a + 6/ \ Va — 6 + Va + 6 Va — b — V Solve the following equations : 124. V» + V^^^ = V5. '^' »' 125. V3a;-2 4-V3^-2 = 0. <) ^ '^t^ 126. Vic + 6 + Va;-4 = 2. ~ U » £> 127. Va; + 2 + V4« + l = V9a; + 7. 't -^ "^ 128. VS^+T - V2x + 3 - V2a;-2 = 0. 129. V2 + V4^+5 = V2¥T3. 130. -^+ 1 2 V^^=^ Vx+^ Va^-4 4 131. -Va;-V4+^ = 0. V4 + a; 132. ^ 4- ■'^ aj + Va^-3 a;-V^233 3 133. 134. GENERAL REVIEW 2-x X V2 + Va; V2-Vx 2 m — n V2m^ + n V2 mx — n x + n Simplify 135. (V^ri)3+(V^/. 136. (V^=^)'-(V^^ 137. (l_V^2-h(l+V^^)2. 138. (i-2V^^y + 2(2-^^iy. 139. (V3 + V^)(V3-2V^). 140..^(2y3-3V^^ 141. (-|+iV33)3. 142. V4 V6 - 11. Rationalize the denominators of : V^ _. 2V18 115 143. 144. V^18 V2 145. 146. -V28 147. 148. V5- 32+2V^ What are the conjugate imaginary factors of : 149. m-{-2n? 150. a^ + T? 151. 3^2 + 2? 116 QUADRATIC EQUATIONS QUADRATIC EQUATIONS I. NtBIERICAL QUADRATICS Exercise 51 Solve : 1. 2x^-7x = W, 11. x'-Q^O. 2. 2x'2 + a; = 15. 12. x'-4.x = 0. 3. 3a:2_^7^.^20. 13. a^ + l = 0. 4. 6x^-19x = S6. 14. 3a^ = 7. 5. 5x2 + 14aj = 3. 15. 5ar'=llx. 6. a;2 + 3a;4-l = 0. 16. 2a;- + 3 = 0. 7. .T2 + 3a;4-3 = 0. 17. 5ar-3x + l = 0. 8. aj2_5a;_i = o. 18. 3«2_^5^,_^3 ^q 9. .T2-5ic + 7=0. 19. 5a^ = 2a; + l. 10. 3a;2 4-2iK + l = 0. 20. 7ar = 6x-l. 21. 3ar^ + .^'-5 = a;2-ll + 8a;. 22. (2x-^S)(x-5) = (x-5)(x + S). 23. (3aj-7)(2a; + l) = (5a; + 2)(2a;-3). 24. (2a; - 1) (3a; + 5) - (a; + 5) (3ic - 2) = 5 - (« - 2)1 25. (3x+ 1) (a; - 5) - (2a; - 1) (3a; + 2) = (a; + 6)^ - 1. 26. (x -5y-(2x- 3)2 _ (a; + 4)2 = a; (a; - 5). 27. (2 a; + l) (a;- 5) +2(a;- 3)2- a;(a; -4) = 2(a;-|)2-15|-. 28. (a; - 5)2 - (3 - 2x)2 - (2a; - 1) (a; + 4) + 5a; = 0. 29. 2(a; + 2) (3a; - 1) - 3 (a; + 1) (4 - a;) = x(a;- 2) - 17. QUADRATIC EQUATIONS 117 30, ^ + -^ = 1. 40.^-1 = ^. x — 1 x-^1 x + 2 a; + 4 31 ^-1 1^ 1 41 2a;-3 a;-! ^ .^ *a;4-la; 6* *3a; — 2 x 32. ^-4 = _^. 42. 1-1=1 - + 2 3-a; 5 9-2ic 3 x 2a;-l 33. ^^±^-^:z2^ii 43. _J ^ + _5_^0. a;_2 a;4-2 ^ a;-l cc + l 2-a; 34. 2^^ + 2^+5 = 2. 44. -5 ^+-A_=0. 2a; + l a; + 8 2a;-7 a;+4 a;+7 35. 4^Zli + §-l = 0. 45. _2_= J0_ _^. 2a; + l 2 a; x-2 x-\-2 x'-4. 3g _^ fl^-1 ^2 46 ^-3 24-a; ^ (a?+iy+4 x — S x-\-3 ' ' 1—x 1+x 1—x^ 2^ a; + 3 3x-2 ^^ ^^ 2x-l x-2 ^ x-S *« + 5 aj — 5 ' x — 2 aj — 3 a; — 4 ^„ 2a;-l a;-2 q ^o 2«-1 a;-7 . 3a;-l 38. T = o. 48. -=4 — . X x-\-l a^H-l a;— 1 x-\-2 39. ^Zll + ^Z:5 = 3. 49. ^±l-^^±?+^!=5 = 0. a;-2 a;-4 a;-3 .t+3 ^9-a^ 50 2a;4-l -^ x — 4. __ —7x 2x-8 2a; + 3 9-4ar' 2 a; — 3 a.' + 13 _ 13 a; — 5 a; — 3 ~~2a; + 5 52 5 a;-1^ 2(a;4-3) ^ 2a;-l a; + l 2a; + 3 53 a; + l ^ 2a;-3 ^ 36 3a; + 2 3a;-2 4-9a^ QTIADBATIC EQUATIONS 60. 2V^=Va;-3-f 3. 61. V2x-l = Vx-\-l. 118 54. 3VaJ + 2 = 2a;-5. 55. a; + 5 = 2V5 oj + l. 56. V3 a; + 7 — a; = 3. 57. 2V3 a;-f-4 = VSa^-S a;-4. 63. 2Va; + l - V2a; -f 3 = 1. 58. 2V^ = a;-3. 64. 2 V3 a; + 7 + 1 = 3 Va? + 3. 65. 5Va;-l-3V3a;-2=-l. 62. Va;4-l-l=V2a;-5. 59. 2 Va? — 1 = a; — 4. 66. 2V3a;-2-3V^+3 + l = 0. 67. Va; + l+V3a;-f4 = V5a; + 6. 68. Va; + 5-V2a;-7= V5. 69. 2 Va; + 1 + Va; - 2 = V7 a; + 4. 70. V4a;-3-V2a; + 2=Va;-6. 71. ■y/Sx-5-{-Vx^^ = 2Vx'^^. 72. V2-3iB-V7 + a;=V5 + 4a;. 73. V3a; + 2-V2aj + l=V^Tl. 74. V2aj + 3-V8a; + 5 = -V4a;-l. 75. 2V3a; + 2-V6a;-3 = 3V3a;-l. 4 76 . V3a; + Va; — 2 = 77. V3a; + 1-V2a; = ^/x-2 5 78. V3a; + 3-Vaj-l = V3a; + 1 2 79. 3V^qp4_V2a;-9 = 8 V2¥^^' QUADRATIC EQUATIONS 119 3 80. V3a;-5+ ^_ = 2V^^=^. ■Vx — 1 81. Va;4-2 = 82. 83. 84. + Var^ + 7 'aj-V^+T II. LITERAL QUADRATICS Exercise 52 Solve: 1. 2a^-5ax = Sa^ 10. aar' 4-aa; + 2 =2a-a?. 2. 6aV-7aa; = 20. 11. 2a^ + a2 = a; + 3aa; + l. 3. Sx^-abx-2a^b'^ = 0. 12. ar'+aaj-2a;+l=2a2+a. 44. 5 aV -24 62 = 26 a6a;. 13. 2d'x'-a^x-9ax=a'-9. 5. 18 6V = 3 6ca; + 10 c^. 14. 6x'+ax+Sx=a'-{-a-2. 6. (B2-2aa; + a' = 4. 15. a V - a^ + 2 6a; = ft^. 7. o^-a^ + 6x + 9 = 0. 16. 6 V+a6a;-4 ar'=2 a(3 a;+a). 8. 4a^ = 4aa; — a^ + l. 17. a^a.'^— a;— aa:^— aa;=(a+l)^. 9. aa^ = 3a; + 4a-6. 18. 4:af-4.ax = b-a^ + c. 19. 4:a'x(x + l) + (a-l)(a + l) = 0. 20. a2a^-62 = aa;2 4-6aj. 22. 4a^-a2 = 2a + l. 21. a^a^ - (6 -1)=^ = 0. 23. 9aV-c2 + 6c = 9. il^O QUADRATIC EQUATIONS 2^. 2aa^—bx = cx. ^^ 1 , 1 a + b 6o. \- = — 25. 3ax' + 4.bx + 5c=^0. « + ^ ^ + ^ ^^ 26. aay^-\-2bx-\-3c = 0. ^q __j^_ = l_i^l. „ ' x — a-\-b X a b 27. arH-pa; + g' = 0. 28. lx^-mx-lm = 0. 37. ?iL±_? + ^Lul^ = 2|. 2a-a; a4-2a; ^ 29. a;2-2aaj-2a;+a2H-l=0. 30. (a2-6>2^a2(2.'c-l). 31. (l-a'){x-\-a)=2a(l-x') 30. (a2-6>2_a2(2.'c-l). 38. ^L_J_ 1^_ 2a = 0. a 39. a; a;— 1 1 111 32. - — bx = — a. a — x b — x a b x — 1 o^ ^ .^ x — a 2a , 2x-\-3a a; g — 1 _ a;H-2 . 18a -. _ x-{-a a + 2 X ~x(a-\-2) ' 5a—x—Sb ~ x-^2b' 42. ax^-^^^^±^ + bx-^ = -^^-bx. a — b a—b 43. ^ 1^ 3a^-2a ^^ _1- + -J l-=0. a; (a — 1) (2 a — 1) a; + a x + b x -{- c 45. V2ar* — ax — a + 2 = a — 2. 46. V3 a^ — 4 «.« + 1 = 2 (a; — a). 47. Va; — a+V3a; — 2a=V2a; + 5a. 48. V^ + "^ a — Vaa; H- a^ = Va. 6 a 49. V^^-^ -^ = — Vx-b. ^x — a Va; — b 50. V6 + a; — V6 — x = V&. 51. 4a;(Va — «) = a — 6. QUADRATIC EQUATIONS 52. Vx -\-a^-\- ^x — 2d^ = V3 x. 121 53. V3a^-4aa; + l=2(a-l). 54. ^/2a^x^ — 6ax — a^-\-5 = a — l. 55. Va; — a — Vcia; = Va; + a. 56. Vax —b — -Vax +b = ■\/arx -\-2ax — (ib. III. EQUATIONS IN THE QUADRATIC FORM Exercise 53 Find all of the values of x : 1. a5^-13a.-2H-36 = 0. 15. 3a;* + 4a;^ = 4. 2. 4a;^-29a;2 + 25 = 0. 3. 9a;^-28a^ + 3 = 0. 4. 9a;^+29aj2 = 80. 5. aj4-16 = 0. 6. 0^4-8 = 0. 7. a^-a; = 0. 8. 2«*-a^ = 15. 9. x^ — x = (}. 10. a;^ + 64a; = 0. 11. a;^ = 7a^ + 8. 12. 8a^ = 27. 13. a; + 4Va; = 5. 14. 2 a;^ — 5 a.'^ = 3. 16. 9a;3_37a;^ + 4 = 0. 17. 3a;4-5a;* = 12. 18. 12 a;^- 11 ^ = 15. 19. a;«-7ar^ = 8. 20. 4a;^-17A/^ + 4 = 0. 21. a;'' 4- 26^/^ = 27. 22. a;^ + a^ + 1 = 0. 23. a;-i + a;"^ - 6 = 0. 24. 2x-'-5x-'=:12. 25. Sx~^-^7x-^ = 6. 26. 2</x- 7 a5-3 = 4. 27. 9x-^ + 4 = 37-J/^l 28. 2.T~^-5v^^' = 3. 122 QUADRATIC EQUATIONS 29. 8-s/F^ = 15^^3 + 2. 36. V3^^-3^/3"^^ = 10. 30. 3x-^ = U-19VsF'\ 37. 2V5a; + l4-^5a;+l = 6. 31. 4a;-^ + 4a;-^ = 3. 38. ^2^31 4. 3 -^2 a; - 1 = 4. 32. (x + iy = 3(x + l)-\-A0, 39. 2(a; + l)*-3(a; + 1)^ = 2. 33. (x'+3xy-2(x'+3x)=S. 40. (4 » + 3)^-^/4^+3 = 6. 34. (a^-4a;)2-9(a^-4a;)=36. 41. 3 V3^+l + -</3^+l=14. 35. (a;-l)*-13(a;-l)24-36=0. 42. 2(2a;+3)-6V2a; + 3 = 3. 43. 2a^ + l-2V2ar^ 4-1 = 3. 44. ic2-a; + 4-6Va:^-x + 4 + 8 = 0. 45. (a^-xy-a^-{-x = 30. 46. 3ic2_4^^3y3ajj_4a._^2 = 2. 47. 2a? + 3x-\-V2a^-{-3x-\-7 = 5. 48. i»2 = 8-3a;-4Va^ + 3a;-3. 49. 3a^-aj = 6V3a^-aj-6 + 22. 50. a^ = 5x + 10-2V3f-5x-2. 51. 2a^ + a; + 5 = 5V2a;2 + a; + l. 52. (a^-x + iy = 3a^-3x-^l. 53. ic2-a; + 5V2a^-5aj + 6 = |(a;4-ll). 54. V2^+9^T9+V2^^+7¥+5 = V2. 55. aj(2a;-3)(2a^H-13aj + 20)=0. 56. ax(x-l)(x'-{-l)(x'-S) = 0. 57. (a^-x-12)(x'-hx-90)(a^ + x-110)=0. SIMULTANEOUS QUADRATICS 123 SIMULTANEOUS QUADRATICS Exercise 54 Solve : 1. 2y-Sx = 7', 3a^-4a^-42/2 = 15. 2. 0^ + 2/2 = 58; xy = 21. 3. 3a^-2a^ = 24; 5a^-4/ = 44. 4. a? — 2 y = 1 ; fl;2/ = 3- 5. x' + xy + f = lS', a^-xy-hf = T. 6. 2a;-2/ = 7; &a^-Sy^ = -7. 7. 3a^-52/2^28; 3 ajy - 4 2/^ ^ g^ 8. 2a^ + a52/ — 2/^ = ^;^ + ^ — 2/^ = 1' 9. 3a; + 4?/ = 2; ar^ - oji/ - 5 1/^ = 1. 10. a;4-3y = -4; 6a^ + 13 a;2/-5/ = 21 2/- 12a? + 18. 11. a;H-2/ = 7; a^ + 2/^=29. 12. a^ + f=21S', x-{-y = 2. 13. a;2/ + 32/^ = 20; a^-3icy = -8. 14. a;4-32/ + 4 = 0; 2a^-52/^ = 5. 15. 2a;-32/ = 3; 4:0^-15-7 xy = 0. 16. a^-a^ + 2/^=21; 3^ + 2/^ = 189. 17. 3a^-52/2 = 7; 4:Xy-y^ = 7. 18. 6a;-82/ + 23 = 0; 32/^-5a^-2a; = 26. 19. a;-2/ = l; a^-2/3^i^ 124 SIMULTANEOUS QUADRATICS 20. 2x' + 3xy-4.f- = 10; 7x~5y = 9. 21. ar^_3/ = l|5 2x2-j-/ = 4f. 22. 1 = ?. l_l = l 23. a;2_^^_j_^2^3^. ^_^^^^,^ 24. (^ + 2/)'-5(x-}-?/)=36; 9a;-42/ = 29. 26. 3a^ + 22/ = 13; a^z/2_^y_30 27. 3a;2 + 52/- = 17; Aa^-3y'=lS. 28. 0^ + 2/2=62-3^-2/; a:?/=14. 29. 2a^-3aJ2/ + 4/=6; x'-^Sf = 7. 31. a^H2/'=626; x-^y = 6. 32. 2a;2 + a;y/_32/2 = 8; a;2_2^2_7 3^ 3x2-5/-3.T-22/ = 9.; 2x~3y = l. 34. 0.-^ + 2/5 = 1056; a; + 2/ = 6. 35. a;-i_2/-i = l; a;-3 _ 2/-3 ^ 3 j^ 36. a; + a^2/ = 2; 2/ + a?2/ = 4i-. 37. 3x'-{-2xy-2y' = 6', 2x' + xy~3f = 3. --38. 0^-2/2 = 16; a^ + 2aJ2/ = 4-2/2. 39. xy = l^- 2x-5y = 2. 40. a;2_|_^2^^^^^20; x + y = 3. 41. -1 L_ = _44. ? . 4_J^ «-2/ 0^4-2/ ^ ' x^y xy SIMULTANEOUS QUADRATICS 125 42. --^ = -2|; 2x-^3y = 2. y X 43. 2x + y + 2xy = 5; x-\-3y + 2xy = l, 44. 2x + 3y = 10; 23^f + ^5xy = 72. 45. a?2_^X2/ + / = '^; ^-^2/ + / = 19. 46. 5a^-2/' = ll; 3a5?/ + / = -9. 47. a^/ + 14a;2/ + 24 = 0; Sx + y = 5. 48. a; 4-2/ = 4; aj* + 2/^ = 82. 49. x^ + f = S7) x'y-{-xy' = -12. 50. a^ + i/2-5aj + 52/ = 30; a;2/ = 8. 51. x' + xy + f = 19; x' + xV -]- y' = 931. 1 1 ^ 1 I 1 fti 52. i_± = 4; - + - = 8|. a; 2/ aj2 2/ 53. x-V^ + 2/ = 9; ^2 _^ 0^2/ + 2/' = 18^- 54. a^4-2a^2/ + 32/' = ti' + 262; x + 2/ = «- 55. o^ + y^-{-x-y = 32', xy = 10. 56. 0^*4-2/^ = 5; a;*2/^ = 6. 57. x^y=-117', Vx+-y/y = 3. 58. aj^-22/^ = l; x-Sy = 19. 59. x2 4-a;2/4-2/' = '^5 a^' + «'y + 2/' = 91.- 60. a; 4- 2/ = 3; x^ + y^ = 33. 61. a;2 4-42/'-x-22/-42 = 0; a;2/ = 12. e2. a^-f = m', x^y-xy^ = 30. 63. a;-2/ = 2; Vac4-V2/ = 2. 64. x + y = 13 + V^) a^^f = 273-xy. 126 PBOPERTIES OF QUADRATICS 65. J^+2Jl = 3; x + y = 5. ^y ^x 66. 2a; + Vi^=12; 2/4-V^=l8. en, x^ + xy-\-y'^ = 3? — xy-\-y'^ = l. 68. x^ -\- y^ =^ xy = 1. 69. or — y"^ — xy = x-{-y. IQ. x^ + y'^ = Zxy-l; x^-^y^ = ll. 71. ^ + ^ = _26: 1^ + 51^=1. 2a 6 X y 72. (a;-22/)2-a; + 22/ = 6; 3a;-52/ = ll. 73. a;y + a; + 2/ = 7; o^ (a; + 2/) = 12. 74. 2a:2_^3y2^8. 2(a;- l)2 + 3(2/ + l)2 = 5. 76. x^^^/'^^aj^/^ig. x-\-y = xy-7, PROPERTIES OF QUADRATICS Exercise 55 Form the quadratic equations which will have the following roots ; 1. 7,5. 7. 0, 5. 2. 2, ^. 8. -2i, 0. 3. 6,-4. 9. a,-l. 4. 4, -If 10. 7,-7. 5. if 11. V5, -V5. 6. -1, i- 12. V-3, -V 3. 13. a, a — 1. 14. 3+a, -3-2a. 15. 2.1-3«. 16. ±10. 17. ±\/a-l. 18. 1 + V2, 1-V2. PROPERTIES OF QUADRATICS 127 19. 3±V2. 20. ±Vll-5. 7±V70 21 22. 2 3±V3 23. 24. -7± V5 a± Va'-l 25. 5±V-1. 26. 27. 28. 29. 30. 5± V^r2 -7±2V-1 2 5±3V^ Without finding the actual values of x, tell what the sum of the roots is ; their product ; their character : 31. x^-5x-24. = 0. 32. a^ + 5a;-l = 0. 33. 2a^-3a;-f 1 = 0. 34. 3a^H-«-10 = 0. 35. x^-Sx-^5 = 0. 36. 5a^-6x-\-2 = 0. 37. 4a^+4a; + l = 0. 38. 4ar2 = _a;-f4. 39. 9x^ + 1 = 6x. 40. 12af-\-7x = -6. 41. 4a^-3a; = 0. 42. 4a^ = 7. 43. x'^-x = l. 44. 3x^-i-5x-}-3 = 0. 45. 25ar^ = 10a;-l. 46. 3a^4-5a; = 0. 47. 3a^ + 5 = 0. 48. 2a^-a; = l. 49. 16a^-40a; = -25. 50. 7a^ + 13ic = 5. Find the values of k which will make the following equations have equal roots : 51. 2x^-2x-\-k = 0. 52. ko(^-4:X-\-S = 0. 53. x^-\-x = — k. 54. kx^=:3x-2. 55. Sx^ + 2x = l-k. 56. A;a^-A:a; + 1 = 0. 128 PBOPERTIES OF QUADRATICS 57. 5a^ = 4a;-2A;4-l. 61. 4.x' = kx-k-5. 58. a:^-kx-^9 = 0. 62. lla:^-\-l = 3x-kx^-\-kx. 59. kx^-i-kx = -Sx-9. 63. ka^-kx=7 x^-j-9 x-25. 60. ic2 + 49 = A'x + 3a;. 64. 3feic2+6A;=5a;(A;4-3)-7. Resolve into factors : 65. a^-3a; + l. 68. a^ + 4. 71. a^-Saft + fe^. 66. x^-x-3. 69. a^ + ic + l. 72. 17-8a; + a^. 67. Sx^-2x-2. 70. x^-lxy-y\ 73. 5a^ + 8a;-2. 74. Explain the rules for determining whether the roots of an equation are real or imaginary. Equal or unequal. Rational or irrational. 75. If the sum of the roots of a quadratic is 3 and their product is 2, find the difference of the roots. Find the differ- ence of the squares of the roots. Find the sum of the recipro- cals of the roots. 76. Find the condition that one root of ax^ -\-'bx-\-c = shall be the reciprocal of the other. Find the condition that one root shall be double the other. One three times the other. 77. If m and n stand for the roots of 2 ic^ -f 5 .'c — 3 = 0, find the values of : (a) m + n. (c) m — n. (e) — | ^ m n (b) mn. (d) m^ — n\ (/) m^-\-7i\ 78. Find the values of the same expressions in the equation 3 a:^ = 13 a; + 10. Also in equation 3 .t^ — a^ + 1 = 0. 79. Form the quadratic whose roots shall be | and |. Form that whose roots shall be | and |. Compare the results. hatio and propohtion 129 RATIO AND PROPORTION Exercise 56 1. Find a mean proportional between 5| and 27. Between m and n^. Between -— and ' ^ » a a 2. Find a fourth proportional to 3, 5, 12. To a, a + 1, a^. To 6, 8, lOf To 8, lOi 6. 3. Find a third proportional to 4 and 10. To 3 and 3|. To a and a; - 1. To i and |. 4. Solve 2a;-l:3a;-2 = 3(a; + l):5a; + l. 5. Solve a;-5:3a;-fl = 5-8a;:3(l-2a;). 6. Solve l:l = -l_:i. a 6 a—b or 7. Solve — : -— ! — - = x:a-\- c{a-\-c) a^ — c^ a — c 8. Solve 2x^-3x + l:3x'-3x-^l = Say'-2x-5:4:x'-2x-5. 2a^-4:X-l x'-\-x-2 9. Solve 2a^-f2a;-l a^+13a;-2 10. Solve .^ + 3a.-7^a^ + 4a. + 10, a^ — 5a;4-6 a:^ — 4a; + 4 11. Solve ^^-^^-^==^ + ^ + ^. 12. Solve ^-2.^-4-2 2^ + . ^1 a^_3ar^ + 2 2x2-x-l 13. Solve V« + 4 : Va; - 1 = V6 a; + 6 : V5 a; — 9. 14. Solve V3a;-2:V4a; + l = V7a; + 2:2V5aj-l. R. & S. EX. IN ALG. — 9 130 RATIO AND PROPORTION 15. Two numbers are in the ratio* of 3 : 7 and their sum is 60. Find them. 16. Three numbers are in the ratio of 2 : 3 : 4 and their sum is 63. Find them. 17. Find two numbers in the ratio of 2 : 5, the sum of whose squares is 464. 18. Find three numbers in the ratio of 1:2:3, the sum of whose squares is 126. 19. What number added to each of the numbers 2, 5, 11, 15 will make the sums proportional ? • 20. Find a mean proportional and a third proportional to 5 and 20. Also to 3i and H. 21. It a: b = c:d, prove the property of " composition '^ by use of the equivalents, a = bx and c = dx. Prove " division " by the same method. 22. If a:b = c:d = e :f=g : h, prove by the method of example 21 that a-\-c-\-e + g'.h-\-d 4-/4- h = a:b=c: d = etc. 23. If a: b = c: d, prove that a4-3c: b-^Sd = 2 a-\-c: 2b-\-d. 24. If m : n=p : q, prove that m-^n : p-\-q = m — 2 n : p—2 q. 25. It X : y = z : w, prove that x^ -\- y^ : z^ + iv^ = (x — nyy : (z — 7iwf. 26. It p : q = r : s, prove that Vi>^ 4- 7^ : Vg^ -\-s^ = ap — br:aq — bs=p:q. 27. It a:b: :b :c, prove that a-{-Sb:b-\-Sc = a:b by use of the equivalents a = cx^ and b = ex. 28. If 2/ is a mean proportional between x and Zj prove that x-2y:y-2z = 2x-'^y\2y-^z. RATIO AND PROPORTION 131 29. If a, b, c, d are in continued proportion, prove by use of the equivalents a = da?, b = daf, G = dx that a + 6 + c : a + & = 6 + cH-cZ:54-c. 30. If a, b, c, d are in continued proportion, prove that a-\-b^:c-\-c^ = b-{-c':d-\-d\ 31. If a, b, c are in continued proportion, prove that a + b :b + c = b^: ac^. 32. If a, b, c, d are in continued proportion, prove that a^^b' -{-(?: b' + c'-\-d'={a + c){a-c):(b-\-d){b-d) = a':b^ 33. If _^_ = _L=_!_, prove that x-y-{-z = 0. b + c a-\-c a — b 34. If _l_=_!^ = _i!_, prove that l + m + n = 0. b — c c — a a — b 35. If a + 2b-\-c:b-\-c = a-{-b:b, prove that 6 is a mean proportional between a and c. 36. Find two numbers in the ratio of 2 : 3 such that the sum of their squares is to their product increased by 2, as 2 : 1. 37. If 1 be added to each of two numbers, their ratio is 1 : 2. The difference of their squares is to 3 more than their product as 5:3. Find them. 38. There are two numbers such that the ratio of the sum of their cubes and the cube of their sum is 7 : 1 ; and if 6 be added to each, the ratio of these sums is 1 : 4. Find them. 39. For what value of x will 2 a; — 1 be a mean proportional between x-\-5 and 4 a; — 13 ? 40. What values must x have in order that 2 a; — 7, 3 a; + 1, 4 a; — 3, 5 (a; + 1) may form a true proportion ? 132 VARIATION VARIATION Exercise 57 1. li X varies as y and y = 2 when x = 12, find x when y = ^. 2. It xccy- and x = ^ when y = ^, find ?/ when a; = 18. 3. If A varies inversely as B and A = — 6 when ^ = — i find ^ when -B = |. 4. If ^ varies jointly as B and C and ^ = 9 when 5 = = 6, find A when B = 5 and O = — 8. 5. If 07 varies directly as y and inversely as z, and a; = 2 when y = 3 and 2 = 6, find «/ when x = S and 2; = — 3. 6. li xccy and a; is 3 when y = -|, find an equation between X and y. 7. If ic X - and ?/ = — 5 when a; = 2, find the equation joining X and ?/. 2/ 8. If a; X - and a; = 15 when y = 5 and 2; = 4, find a; in terms z of 2/ when 2 is — 1. 9. If a! X (2y + 5) and a; = 3 when ?/ = — 2, find y if x = 6. 10. Given that ?/- x (a;^ + 1) and a; = 7, when j^ = 10, find x when 2/ = VTO- 11. If u is equal to the sum of two quantities, one of which varies as x and the other inversely as x, and if u = — l when a; = |, and w = 1 when a; = 1, find the equation between u and X. 12. If V is equal to the sura of two quantities, one of which varies as a^ and the other inversely as 1/, and v = — 1, when X =^, y = 2', and v = 7 when x = 2, y = 3 ; find the equation for V in terms of x when ?/ = — 1. VABIATION 133 13. Given that y = the sum of three quantities which vary- as X, x"^, and x^ respectively. When x=l, ?/=4; when x=2, y = S\ when x = 3, y = IS. Express y in terms of x. 14. If y varies inversely as ar^ — 1 and y = — 5 when a; = 4, find X when y = — 15. 15. If y varies inversely as (2 x + 1) (x — 3) and y = — \ when a; = 2, find a; when y — 1\. 16. If the area of a circle varies as the square of its radius, and the area of a circle whose radius is 7 is 154, find the area of the circle whose radius is 10. 17. Find the radius of the circle equivalent to the sum of two circles whose radii are 5 and 12 respectively. 18. The pressure of the wind upon a plane surface varies jointly as the area of the surface and the square of the wind's velocity. The pressure on a square foot is 1 pound when the wind is blowing at the rate of 15 miles per hour. Find the velocity of the wind when the pressure on a square yard is 36 pounds. 19. If w varies as the sum of x, y, and z, and tv = 3 when a; = 3, y = — 4:,z=6, find xiiw = — 3,y = 3^,z = — 9. 20. If w is equal to the sum of two quantities, one of which varies as x, and the other jointly as y and z, and w = — 3 when a; = 2, 2/ = 6, 2 = — 1; and w = — 2 when a; = 4, ?/ = 2, 2; = — 3 ; find the equation combining the four quantities, w, x, y, and z. 21. If the square of x varies as the cube of y, and a; = 3 when y = 2, find y when x = 24. 22. The area of a triangle varies jointly as its base and altitude. Find the altitude of a triangle whose base is 23, equivalent to the sum of two triangles whose bases are 15 and 22 and whose altitudes are 10 and 12 respectively. 134 ARITHMETICAL PROGRESSION ARITHMETICAL PROGRESSION Hzercise 58 In the following 16 examples tell what a is, what d is, what n is. Also find I and s in each. 1. 5, 7, 9, •••, to 15 terms. 2. 6, 9, 12, ..., to 10 terms. 3. — 2, — 31 — 5, •••, to 45 terms. 4. 3, 3.1, 3.2, ..., to 300 terms. 5. 8, 7.5, 7, •••, to 60 terms. 6. 2|, 2^,21, ..., to55terms. 7. - 3^, - 2f, - 21 .-., to 75 terms. 8. 1 + a;, 1 + 3 a;, 1 + 5 X, • • •, to 10 terms. 9. Odd numbers to 37 terms. 10. Numbers divisible by 7 to 15 terms. 11. Numbers divisible by 3 to 20 terms. 12. 5, 10, 15, •••, to r terms. 13. 1, 2, 3, 4, •••, to X terms. 14. 2, 6, 10, 14, ..., to w terms. . 15. The first n odd numbers. 16. The first 2 71 even numbers. Insert, between 17. 11 and 32, 5 arithmetical means. 18. 7^ and 30, 9 arithmetical means. ARITHMETICAL PROGRESSION 135 19. 38| aud — 44|, 99 arithmetical means. 20. 17 and 3, 12 arithmetical means. Find d and s if : 21. a = 5, Z = 25, n = ll. 23. a = 4, Z = 36, n = 24. 22. a = -13, Z = 26, n = 14. 24. a = 12i, ^ = - 13|, n = 40. Find n and s if : 25. a = 6,d = 2,lz=S0. 27. a = 3J, c? = J, ; = lOf 26. a = -17, d = 4, ^ = 39. 28. a=9i, d = -i, l = -W^. Find a and s if : 29. d = 3, ^ = 38, n = ll. 31. d=-2,l=-25,n = 27. 30. (7 = 1|, Z = 69, n = 41. 32. d = -|, Z = 6^, n = 20. Find Z and d if : 33. a = 5, n = 9, s = 297. 34. a = 3J, n = 15, s = 78|. 35. a = -l|, n = 30, s = 530. Find n and d if : 36. a = 8, ^ = 41, s = 294. 38. a = 8, Z = 0, s= 100. 37. a = 3i Z = 42|, s = 621. 39. a=-3^,Z=-36,s=-790. Find a and /, if : 40. d = S, n = 13, s = 260. 41. d = i, n = 20, s = 102|, 42. d = -f, n = 8o, s = -306i. Find a and d, if : 43. Z = 47, n = 23, s = 575. 44. Z = ll|, n = 37, s = 209J. 45. / = -16^, n = 43, s = 43. 136 ARITHMETICAL PROGRESSION Find n and ?, if : 46. a = S, d = 2, s = 80. 47. a = 2, d = -S, s = -328. 48. a = o, d = — ^, s = 27. Find n and a, if : 49. d = 5, l = S2, 5 = 119. 51. d = l, 1 = 6, s = 45. 50. d = -^, / = 5i s = 2o. 52. fZ = -|, / = -3, s = 13. 53. How many numbers are there between 100 and 1000 that are exactly divisible by 7 ? Find their sum. 54. Find the sum of all the numbers of two figures each that are divisible by 8. 55. Find the sum of the first 50 odd numbers. 56. In the series 2, 5, 8, •••, which term is 98 ? 57. How many terms must be taken from the series 3, 5, 7, •••, to make a total of 255 ? 58. Which term of the series li 2, 21 •••, is 24? How many consecutive terms must be taken from this series to make 84? 59. The 7th term of an A. P. is 17, and the 12th term is 27. Find the 1st term. The 3d term. 60. The 10th term of an A. P. is |, and the J 8th is 3f . Find the 1st term. The 100th term. Sum of 20 terms. 61. How is a single arithmetical mean between 2 numbers found most readily ? How do you determine whether or not 3 numbers are in A. P. ? 62. Find x, so that 3 — 5x,l-\-2x,4:-\-7x, shall form an A. P. 63. The sum of 4 numbers in A. P. is 46, and the product of the 2d and 3d is 130. Find them. 64. The sum of 3 numbers in A. P. is 27, and the sum of their squares is 275. Find them. ARITHMETICAL PROGRESSION 137 65. A body freely falling from a position of rest will fall 16 J^ feet the first second, 48^ feet the second second, SOy^ feet the third, and so on. Find the distance fallen during the 10th second. How far in 10 seconds? How far in 20th second? How far in 20 seconds ? 66. Find x, so that S -{- 2 x^ 5 -{- 6 x,9 + 5 x, shall form an A. P. 67. Which term of the series 2^, 3f, 5, •••, is 45 ? 68. How many consecutive terms in the series 2^, 3|, 5, •••, will make 67^ ? Interpret the negative result. 69. If the 6th term of an A. P. is 9 and the 16th term is 22J, find the 25th term and the sum of 30 terms. 70. Find the sum of the series x, Sx, 5x, 7 x, ••., to x terms. 71. Find the sum of all the numbers between 100 and 600 that are divisible by 11. 72. Find x, so that 2a; — 1, 3a; + 2, 6aj + 8, shall be an A. P. 73. What will x and y each be, if the four terms 2x — y, x-\-2y,3x + y^7x — 10, form an A. P. ? 74. Find the sum of 15 terms of an A. P. of which the middle one is lOJ. 75. Find the sum of '1±1 -f- !?i±^ + ^?i±^ . . . to n terms. n n n 76. A boy travels at the rate of 1 mile the first day, 2 the second, 3 the third, and so on; 6 days later a man sets out from the same place to overtake him, traveling 15 miles every day. How many days must elapse after the second starts before they are together? Interpret both results. 77. The sum of n terms of the series 21, 18, 15, •••, is equal to the sum of the same number of terms of the series 3, 3^, 3_6_, .... Find n. 78. Find the sum of 41 terms of an A. P. whose 21st term is 100. 138 GEOMETRICAL PROGRESSION GEOMETRICAL PROGRESSION Exercise 59 Find I and s in each : 1. 3, 6, 12, •.., to 8 terms. 2. 2, 8, 32, ..., to 5 terms. 3. 40, 20, 10, ..., to 6 terms. 4. 2.1, 21, 210, ..., to 5 terms. 5. 54, 18, 6, ..., to 5 terms. 6. 3.2, 0.32, .032, ..., to 6 terms. '^' ^j f? \h •••? to 5 terms. 8. I, 4^2, ..., to 7 terms. 9. 11 —3, 6, ..., to 9 terms. 10. - 5, 15, - 45, . . ., to 5 terms. 11. 34, If, I,..., to 10 terms. 12. 16J, -111 71 ..., to 5 terms. 13. l+a; + «2 + a^---, to6 terms. 14. 32-16 + 8-4 + 2-1..., toTi terms. Find r and s, if : 15. a = 3, ^ = 48, w = 5. 16. a=^n, 1 = 4.05, n = 5 17. a = 131 Z = 17, ^::=a Find a and s, if : 18. Z=i, 71 = 6, r=i-. 19. / = 85i n = 5, r = lj. 20. Z = |, 71 = 5, r = -2 GEOMETBICAL PROGRESSION 139 Find n and s, if : 21. a = 5, 1 = 160, r = 2. 23. a = 24, /=|, r = f 22. a=3, Z = 1875, r = 5. 24. a = f, Z = -24, r = -2. Find r and r?., if : 25. a = 2, Z = 486,s = 728. 27. a = 1|, Z = 135, s= 201f. 26. a = 56, Z = lf, 8 = 1101 28. a = |, Z = - ^^^ ^ s = - 8|f f . Insert, between 29. 4 and 972, 4 geometrical means. 30. 7 and 896, 6 geometrical means. 31. 5^ and 40 J, 4 geometrical means. 32. 20and— yl-g^, 8 geometrical means. 33. 7^ and ff, 4 geometrical means. Find the sum of each series to infinity : 34. 6,3, H,.... 38. 8|, -6|,5,-... 35. 1, -|, 1 .... 39. 8.3, 0.83, .083, .... 36. 15, 5, If, .... 40. .72, .0072, .000072, .... 37. 18,12,8,.... 41. 1^,0.75,0.5.... 42. 0.4545, .... 44. 3.8181, .... 46. 2.34848, .... 43. 0.05454,.... 45. 5.12727,.... 47. 1.026363,.... 48. If the 3d term of a G. P. is 36 and the 6th term is 972, find the 1st and 2d terms. 49. If the 4th term is 24 and the 8th term is 384, find the first 2 terms. 50. The 3d term is 4 and the 7th is 20^. Find the first 2 terms. 140 GEOMETRICAL PROGRESSION 51. In the G. P. 2, 6, 18, .••, which term is 486 ? 52. How many terms must be taken from the series 9, 18, 36, •••, to make a sum of 567 ? 53. How many consecutive terms in the series 48, 24, 12, •••, are required to make 95 J ? 54. The 1st term of a G. P. is 8. Its sum to infinity is 32. Find the ratio. 55. How can a single geometric mean be determined most readily ? How does one test a series to determine whether it is a G. P. or not ? 56. Find ic, if 2 a; — 4, 5 a; — 7, 10 a; + 4, are in G. P. 57. There are 3 numbers in A. P. whose common difference is 4. If 2, 3, 9, be added to them respectively, the sums form a G. P. Find the numbers. 58. The sum of a G. P. to infinity is 18 and the 2d term is 4. Find the 1st term and ratio. 59. If the series a; -f 1, x-\-S,4:X — 3, is geometric, find x. Find a; if it is an A. P. Find the 4th term of the series in each case. 60. Tell whether each of the following series is arithmetical or geometrical : (a) 3, 6, 12, .... (c) 12, 18, 25, .... (6) 6, 12, 18, .... (d) 3i, H, 0.6, .... 61. The sum of three numbers in G. P. is 65. The sum of the first two is i the sum of the last two. Find them. 62. Divide 49 into 3 parts in G. P. such that the sum of the 1st and 3d parts is 2i times the middle part. 63. The sum of 3 numbers in G. P. is 14 and the sum of their reciprocals is f . Find them. GEOMETRICAL PROGRESSION 141 64. Insert between 6 and 16 two numbers, such that the first three of the four shall be in A. P. and the last three in G. P. 65. If the series 3^, 2|^, •••, be an A. P., find the 105th term. If a G. P.J find the sum to infinity. 66. The sum of $ 240 was divided among 4 men in such^a way that the shares were in G. P., and the difference between the greatest and least shares is to the difference between the other two, as 13 : 3. Find each share. 67. What number added to each of the numbers 2, 5, 11, will make sums that are in G. P. ? 68. Find x, so that 5-\-x, 5 — x, 2(1 — 5 a;), shall be in G. P. 69. If 4 a? — 1, 6 a; + 1 , 5(2 x -f- 1), are in G. P., find x and find the ratio. Also find the next term. 70. If the first term of a G. P. is 6 and the sum to infinity is 18, find the third term. 71. If a man ascends a mountain at the rate of 81 yards the first hour, 54 yards the second, 36 yards the third, etc., how many hours will he require to ascend 211 yards ? 72. There are 4 numbers, the first three of which are in G. P., and the last three are in A. P. The sum of the first and last is 14, and the sum of the second and third is 12. Find the numbers. 73. A ball thrown vertically into the air 150 feet falls and rebounds 60 feet. It falls again and rebounds 24 feet, and so on until it comes to rest on the ground. Find the entire distance through which the ball has traveled. 74. Prove that equimultiples of a G. P. are also in G. P., and that alternate terms of a G. P. form another G. P. 142 PERMUTATIONS AND COMBINATIONS PERMUTATIONS AND COMBINATIONS Exercise 60 1. How many numbers of 5 different figures each can be formed from our 9 significant digits ? 2. How many words of 4 letters each can be formed from the 26 letters in our alphabet, no letter being repeated in the same word ? 3. Find the number of committees, each containing 5 boys, that can be selected from a room of 20 boys. 4. Find the number of combinations of 8 objects each that can be formed from 25 objects. 5. How many different words can be formed from the letters in the word TJiursday, using all its letters each time ? 6. From the members of a party of 30 people, a board of 4 officers is to be chosen. In how many ways can this occur ? 7. From the letters in the word Repiihlican how many words of 4 letters can be found ? Of 5 letters ? Of 7 letters ? 8. The prime factors of a certain number are 2, 5, 7, 11, and 17. How many exact divisors (except itself and unity) has this number ? 9. It is required to place 20 dissimilar bouquets in the form of an arch. In how many ways can they be arranged ? 10. From the 9 significant digits, how many numbers can be formed each containing 1 digit ? Two different digits ? 3? 4? 5? 6? 7? 8? 9? All together? 11. There are 25 points in a certain plane; these are joined so as to form triangles having the vertices at the points. How many triangles will there be ? PERMUTATIONS AND COMBINATIONS 143 12. From the letters in the word handiwork how many words of 5 letters can be formed ? How many of these will contain the h ? the w ? How many will begin with d ? How many will contain both d and i? How many will not con- tain d ? 13. A man has 5 pairs of trousers, 8 vests, and 6 coats. In how many different costumes can he appear ? 14. Six persons enter a car in which there are 10 seats. In how many ways can they be seated ? 15. In how many ways can a baseball nine be arranged provided the pitcher is always the same ? Provided the pitcher and catcher are always the same individuals ? 16. In how many ways can 10 people arrange themselves around a circular table ? 17. How many words can be formed from the letters in the word latin, the 2d and 4th being always vowels ? 18. How many words can be formed from the letters in the word united, the even places being always occupied by con- sonants ? 19. How many words can be formed from the letters in the word education, provided the 2d, 4th, 6th, and last letters are always consonants ? 20. From our 9 digits how many numbers can be formed, each containing 6 figures ? How many of these will contain the figure 5 ? How many will not contain a 7 ? How many will contain both 5 and 7 ? How many will begin with 3 ? End with 4 ? How many will be odd ? 21. From 10 gentlemen and 8 ladies how many committees can be chosen, each containing 3 gentlemen and 2 ladies ? 22. From 10 consonants and 5 vowels how many words, each containing 4 consonants and 3 vowels, can be formed ? 144 PERMUTATIONS AND COMBINATIONS 23. There are 8 Democrats and 10 Kepublicans belonging to a certain board. How many committees can be chosen each having 4 Democrats and 5 Kepublicans ? 24. Out of 4 vowels and 9 consonants there are words to be constructed, each consisting of 2 vowels and 6 consonants. How many can there be ? 25. From 6 white balls, 4 red balls, and 8 black balls, how many combinations can be made each to contain 3 white, 2 red, and 4 black balls ? 26. From 4 labials, 6 vowels, 5 palatals, how many words can be made each consisting of 2 labials, 3 vow^els, and 2 palatals ? 27. How many different sums of money can be made from the following coins: cent, 5-cent, dime, quarter, half dollar, and dollar ? 28. A guard of 5 men must be selected every night out of a detachment of 32 men. For how many nights can a different guard be selected ? How many times will each soldier serve ? 29. A company of 15 merchants, 12 lawyers, and 8 teachers wish to form a commission from their number, consisting of 4 merchants, 3 lawyers, and 2 teachers. How many ways are there in which they can do it ? 30. Find the number of permutations that can be made from the letters in the following words using all the letters : (a) Recess. (c) Bumblebee. (e) Concnn-ence. (b) Possess. (d) Tennessee. (/) Unostentatious. 31. In how many different ways can one mail 4 letters in a village containing 7 letter boxes ? 32. How many different quantities can be weighed with the following weights: 1 ounce, 3 ounces, 8 ounces, 10 ounces, 1 pound, 5 pounds, and 10 pounds? BINOMIAL THEOHEM 145 33. With 2 violet, 2 indigo, 3 blue, 4 green, 1 yellow, 1 orange, and 2 red flags, how many signals can be made if all the flags are used and always kept in a vertical column ? 34. Prom 7 consonants and 5 vowels how many words can be formed, each consisting of 4 consonants and 2 vowels ? 35. A plane is determined by 3 points, if they are not all in a straight line. How many planes are determined by 100 points (no four of them lying in the same plane) ? BINOMIAL THEOREM Exercise 61 Expand : 1. (a-2y. 6. (2m-\-ny. ' 9. (■</6-2)«. 2. (2a + l)^ 6. (3a-Va6)*. 10. (V2-h2V6)3. 3. {l-^a'xy. 7. {a-V^-iy. 11. (Va-Vw)'*'. 4. (1-2/y. 8. (V2-V3)^ 12. (a^-^a^c/. 13. (1-3V3)1 20. r^ + ^Y- 14. (Vi-3V2^)*. 21. {a</x-'-x^a-y 22. (2aV2^+-v/4)*. 15. (V3«-^2a;2/)^ 16. (2-V^^y. ,_ ,, ^ ^ 23. (V2a-</-3ay, 17. (3V-1 + 2V5)'. r2Va^3V2l^ 24. ^ -zzz -\ — — 18. {cix~'^ — •\/a~'^x) • I Vn^ ^a ^^' V^-3V^=3^ . 25. -^-^^ V ^ .S « / la V a V c J R. & S. EX, IN ALG. — 10 146 BINOMIAL THEOREM Find only the term required : 26. TheTth termof (aj + V^)". 27. The 5th term of (1 - 2 xf. 28. The 4th term of (a + 3 ■\/xf\ 29. The 6th term of (2 n ^/m - 1)". 30. The 8th term of (a V^ - a; VaP. 31 . The 7th term of (i - 2 a; ^^)". 32. The 5th term of (Vox +^?y«. 33. The4thtermof (V6- V3)«. 34. TheSth termof (V3 + V-2)». 35. The 7th term of ( V2 - a V3xy\ 36. The 9th term of (J^ ^a + 2 V3^)^. 37. The 4th term of ( V2 - 5 V^^. 88. The 5th term of [^ + -^^^T- 39. The term containing o^ in (1 —xVxy^. 40. The term containing x' in (a;-f 2V^)^. 41. The term containing x^^ in (■\/x—-^xyy\ 42. The term containing x^ in (2 \/x— V2xy. 43. The term containing x-* in f— ^—\ . V6a: V^V BINOMIAL THEOREM 147 Expand to four terms : -I .. 1 44. (a + 6)-^ 52. (x-2-^/ax^-^, 59 3. ^ ' Va-\-2¥ 45. (a-a;)-\ 53. Va^ + Va. o ah 60. 46. (a;-2)-^ 54. (l + 5f(2^x)i ^a'^ - aft^ 47. (a + 2/)i 55. (a6«-36V«)l ^^^ T^^^' 48. (a2_4)-2^ 56. 5(x-^-\/2xy)-K gg. (a2_3V2)l 49. (l-2^-x)-\ 57. C-L_y3^y'^ 63. -—4 Wa J VaVx 50. (aar« + l)^. 58. 64 ax 2y 51. (b^-2by\ a-b^/c (x-2^xyy Find only the terra required : 65. The 3d term of (a + b)'\ 66. The 4th term of (x — y)-\ 67. The 4th term of (1 +3Va5)i 68. The 5th term of (a;- 2 VaJ^) -2. 69. The 5th term of {l-^/2x)-\ 70. The 6th term of (a + V-2«)-^ 71 . The 6th term of (x^y + 3 yVx)^. 72. The 5th term of (x^ - 3 x-\/y)-\ 73. The 7th term of \^=.- a —'-wax 74. The 8th term of - ^^ Vl-4a26 148 LOGAmTBMS 75. The 5th term of '^{a-Q,^cy. 76. The 10th term of — 77. The 9th term of (V2 - 3 V^^)-\ 78. The 8th term of (2 + V^^)~^. 79. The term containing a^ in (1 -\-x)~^. 80. The term containing ic" in (x'^ — 2 x)~\ 81. The term containing x~^ in (v^ — 4Va)^. 82. The term containing a;"'^^ in T^^- ?:^T . LOGARITHMS Rsercise 62 Compute by four-place logarithm tables the values of the following : 1. 55x3.86. 7. 823x756-- 4320. 2. 7.81 X 9.3 X .568. ^ 7.61 x 53.8 x 4.113 3. 8.52 X .0917 X 63.4. * 27.5x1.884 4. .097x63.8x51.14. _ 328x57.42 <7. 5. 8.76 X 95.32 -- 614.3. 134.2x3.876 6. 71.3x5.888-43.18. 10. 123.5x3.586-976.3. 11. 36.95 X 438.7 - (356.7 X 81.44). 87.63 X 563.8 x .0075 91.76 x. 00385x2.1 176 27.51 X 9832 x .0953 ' * 7.143 x .08885 x 11.58 ' LOGARITHMS 149 14. 75 X .03896 x .4427 83 X .008114 X 7.003" 15. 876.4 X 3.175 x .6511 8.465 x .1973 x 598.6* 16. 17. ■v^^9?f6. 18. V17 X 29. 19. ^/365.4. 20. V.0837. 29 5 X 78.3 X19.7 30 31. '■i 9.02 X 1.762 3.117 X .0585' 5/ 17.44 X .( \zt2 11 V 8 .0832 '42.11x8.104* 7.663 X 85.12 x .00681 43.27 X 95.16 x .007194* 21. -v/^00302. 25. -J/7.13 x 41.2. 22. -v/.00075. 26. V10.3^.049. 23. V93 X 2.78. 27. ^361^5.88. 24. ^951 X .037. 28. ^8.95 -f- 16.44. 3^ 853.4 X V:004176 627.1 X ■</ .06329 * -. ^5/ 57.18 X 3. 876 ^^' \7.116x.0 39 X .0485 7/ 5.192 X V63l8 ^ 81.32 X .0638 * 32 ■41 382 X 763.5 .03871 X 8124 33. 34, 35. 36. 4 03765 X 1.448 37.12 X 5.718 .4138 X VaiTr 3.108 X i/Tmi 5.167 X V38:27 77.38 X ^:09034 .7563 X -^2:087 .5432 X </M15 40 41 3/ .07162 X .00328 , ^1.586 XA/37f77 ^/ .0913 X \/:07652 ' ^ 1.517 X 7.038 42. 43. V 3/1.716 X 873.5 .0173xV3967 V 750 x (.83) 97 X (.0361)* 44 3 / 92.3 X .08763 .003151 X 5V30 150 LOGARITHMS 45 J 9.3I0 X -5^7^ 4g 37.5 6 /440V:0074 ^10.14 xV:3876 * 583^ 19^600 47. V8.5I6 X v^9L763 x \/l998. 48. \/53:34xa/7JI6-V98J[5. 49. V8.176 X VMM X VTlI^. 50. -v^l.Tie X 8.513 X VtKM. 61. V73.14X 80.37 -^5768. 52. ^53.11 X V7:852 - 3 VTT^. 63. •v'3V85 X 2^916 x 5^45. g4 J 876.3 X 5.173 x V.()08886 6.385 X 711.5 X v':0l776 * gg J .07138 X V.00885 x ^1:762 .08195 X V.00176 x VsM2 gg^ J 57I.2 X (3.817)' X (.07161)^ ^ 88.19 X (2.716)^ X (1.558)* Solve, by logarithms, the following equations : 57. a; = 19V2l. 61. 38a^ = 235. oa 62. 3V^ = 17. 58. x = -^' Vll 63. 11^ = 13. 59. a;ViO = 95. 64. a;V5 = -5^'50. 60. a^ = 3.47. 65. 97ic2 = V855. LOGARITHMS 151 66. Vl7a; = 67. a/5.5 a^: : 9.74. = V79. ' 72. 38^/^ a;V55 97 79 68. 30xV7: = 6iA/m 73. ^^/ = V190. 69. 13A/15a : = 27V: Oil. 70. 26Vx = a;V33.7. 74. 17 a;"^ = 65. 71. ^'''-. VSx ^4l So; 75. xVSf ^38 75 V^ 76. 5^ = 30. 81 . 65' = 3. 86. 25*-i = ll*. 77. 6'' = 75. 82, . 40* = 5. 87. 552-- = 21*+^ 78. 7^ = 15. 83, . 18.6' = 1.86. 88. (3 + .05)^^=100. 79. 8^ = 100. 84, . 9*+i = 15. 1 89. .9'"^ = 4.7-i 80. 4.5* = 50. 85. . 3^-1 = 36. 90. (1.025)»«=1.01. Calculate : 91. Iog4 20. 95. Iogi6 60. 99. log2jj.68. 92. logy 500 96. logijS. 100. logi2.3 .0423. 93. logs 35. 97. loggl.O. 101. log.5.63. 94. logi3 29. 98. Iog2o.4. 102. log.8.07. 103. Find the amount of $ 575 in 10 years at 5%, compound interest. 104. Find the amount of $ 8500 in 12 years at 4%, compound interest. 105. Find the amount of $3500 in 6 years at 6%, compound interest. 106. At what rate will* $ 12,000 amount to f 14,587 in 4 years ? 152 LOGARITHMS 107. At what rate will $ 8250 amount to $ 11,627 in 10 years ? 108. What sum will amount to $520.75 in 6 years at 5%, compound interest ? 109. What sum will amount to $817.30 in 8 years at 7%, compound interest ? 110. In what time will $5000 amount to $8000 at 5%, compound interest ? 111. In what time will $2750 amount to $5000 at 4%, compound interest? The following examples in this exercise are to be done with- out the use of logarithmic tables. 112. Find the logarithm of 27 to the base 3. 113. Find the logarithm of 3 to the base 27. Find : 114. log4 8. 118. logai- 122. log^^ 81. 115. log25l25. 119. logi8. 123. logaayV 116. log27 81. 120. logioolO. 124. log64 3V 117. logs 32. 121. log^27. 125. log^ooo .01. Find a;, if : 126. log, 8 = 3. 132. log, 27 =-3. 127. log, 81 = 4. 133. log, 64 = - If 128. log, 125 = 3. 134. log, 7 = - i 129. log,6 = f 135. log, 2V = - 11 130. log, 27 = IJ. 136. log, 243 = - 2.5. 131. log,32 = l|. 137. log, J?^ = - .75. LOGARITHMS 153 Find x,{f: 138. log, ic = 4. 142. log49a; = i 146. log27a; = — IJ. 139. logs a; = 3. 143. \og3QX = — ^. 147. logi x = — .5. 140. log9a; = |. 144. log64a; = — If. 148. logo a; = — 3. 141. log8aj = |. 145. logia; = 1.5. 149. logjg a; = — 1.5. Write out as a polynomial : 150. logaV. ,^^ , 11 a;^' 157. log——' 151. logafe^ ^^y 152. log^^l 158. \og4.(x-yy. 153. log^. ^^^' log 8 «'(«'- ^')- c^ 160. log3a(9-n2)i 154. log3aa;^.^ ^^^ log a (a + 5)>3 _ ^s). 155. log -2^- 162. log8a6«-\/5a=^6-^c-i 156. logL^!^. 163. log?^M±^. Change to the logarithm of a single term : 164. log a 4- 3 log 6. 167. log 11 4- i log a. 165. log 7 — 3 log ». 168. 31oga-21og6. 166. logm+i^gT. 169. log 2 + log 3 - log 13. 170. 2 log 3 + 3 log a — log 5 — i log x. 171. log5 + 31ogaj4-ilog2/— 21og7 — ^loga. 172. 1 log 2 — J log a; + 2 log a — I log 2/ — log z. 173. log 7 + 1 log a 4- f log & - log 6 - ^ log c. 174. log (a + 1) + log (a — 1) — log 2 — J log m. 175. ilog(i) + g)+ilogO-g)-ilog(a; + ^)-ilog(a; -»!/). 154 LOGARITHMS 176. log 3 + 2 log 2 + i log 5 - log 7 - log 11 - f log 13. 177. 31og2 + l+|log7-ilog3-^log(a2 + 62)_iog^^ Find a;, if: 178. a^ = bc^. 182. 3a^-2 = d^ 179. 3b' = cd'. 183. a6- = cd'-\ 180. 5m' = ?t2p2*. 184. m^n''-^ = p. 181. a^-^ = b\ 185. (^d = l^^hn'-\ 186. If log 365 = 2.5623, write log 3.65. Log .00365. 187. If log 7.008 = 0.8456, what is log 7008 ? Log 70.08 ? 188. If log 27.8 = 1.4440, write log 27800. Log .00278. 189. If log 536 = 2.7292, and log 537 = 2.7300, what is log 5.365 ? What is log .05368 ? 190. If log 3.71 =0.5694, and log 37.2 = 1.5705, what is log 37140 ? What is log .003717 ? 191. If log 709 = 2.8506, and log 7100 = 3.8513, find log .07096. Find log 70.94. 192. If log 627 = 2.7973, and log 628 = 2.7980, find x, if log X = 0.7975. If log X = 8.7978 - 10. If log x = 3.7976. 193. If log 3.35 = 0.5250, and log 33.6 = 1.5263, find x, if log x = 9.5254 - 10. If log x = 7.5260-10. If log x = 4.5258. 194. If log 2.357 = 0.37236, log 235.8ii 2.37254, and log x = 3.37243, find x. Also find x, if log x = 7.37251 - 10. Given, log 2 = 0.3010 ; find the following logarithms : 195. log 4; log 40; log 8; log 800; log 32; log 3.2. 196. logV2; log ^2; logV^; logv'S; log Vi02. 197. log 5; log 50; log V5; log 2.5; log 12.5; log6J; log f . LOGARITHMS 155 Given, log 2 = 0.3010 and log 3 = 0.4771 ; find the following logarithms : 198. log 6; log 12; log 18; log 15; log 150; log 14.4. 199. log2V3; log3V2; logVSO; log^iOOS; log 45. 200. log 540; log .024; logS^; log 4^; log3|. 201. From log 16 how can one get log 2? Log 4? Log 8? Log 5? Log 25? 202. From log 2 and log 15 how can one find log3 ? 203. From log 5 and log 14 how can one find log 7 ? 204. From log 50 and log 36 how can one find log3 ? 205. From log 14, log 15, log 16, how can one find the log- arithms of all numbers from 1 to 10 ? 206. Show that there will be 31 figures in the 100th power of 2. [log 2 = 0.3010.] 207. How many digits in 49^ ? [log 7 = 0.8451.] 208. Find a; if a*' = &. 209. Findajif a2-' = 2&. If2a2-^ = 2*. 210. Find x, (a) if .6^ = 3, (6) if .08^ = .9, provided it is given that log 2 == 0.3010, log 3 = 0.4771. 211. What is the base if log .25 = - 1 ? If log ^ = 2.5 ? 212. Solve 22^-y = 32 and 3^+^ = 81. 213. Find x and y, if 4^+^^ = 128 and 25^"^ = 125. 214. If log5 = 0.6990, findxin the equations 2*' = 40 and (2*)' = 40. 215. Show that log | + log f^ - 2 log .4 = log 3. GENERAL REVIEW Exercise 63 1. Solve the equation 12a^ — 17 x = 40 for x. 2. Tell by inspection the sum, product, and nature of the roots of 3a^-lla; + 15 = 0, and of 3a^ + lla; = -8. 3. Find the sum of the series 4i, IJ, |, •••, to infinity. 4. Solve for x and y, x^ — jf = 152, and x = % -\-y. 5. Define quadratic equation, pure quadratic, symmetrical expression, homogeneous expression, logarithm, arithmetical progression, geometrical progression, alternation, composition, and mean proportional. Give an illustration of each. 6. Form that quadratic whose roots shall be 1\ and — 2|-. Also that one with — = for roots. 2 7. In the A. P. 15, 131, 12, ••., find the 55th term and the sum of the first 20 terms. 8. Solve the equation a^ — 1000 = for its 3 roots. 9. Solve 2x^ — 3xy -{-y^ = 3, 3x^ — xy = 2, ioi x and y. 10. Which term in the series 2|, 3, 3|, •••, is 65 ? 11. Find all the values of ic in x^ = 9x. 12. When are the roots of la^ -\- mx + n = real ? When equal ? When irrational ? When imaginary ? 13. From the letters in the word scholar, how many words can be formed, of 4 letters each ? Of 7 letters each ? 166 Gi:Ni:iiAL review 157 1 _3 14. Solve 7 X ^ = 8. Are both the values of x roots ? x^ 15. Find the values of a? and 2/ in ar^— 2a;2/— a;=3, 3ic— 42/=7. 16. Find the values of x, by inspection, in 2aa;(ar'-4)(3a^ + 5) = 0. 17. What is the logarithm of 216 to the base 36? Of 8 to the base 128 ? What is \og„ ^J^ ? 18. It a:b = c: d, prove that 19. Write the equation 32^ ^ = 64 in logarithmic form. What is the number? The logarithm? The base? The charac- teristic? The mantissa? Write logs; 243 = 1| as an equation. 20. How many parties of 7 each can be selected from a school of 25 girls ? 21. Solve 2-\/x + 3 — Va; — 2 = V3 x — 2. Are both values of X roots of this equation ? Why ? 22. Find the 6th term and the sum of 7 terms in the series -4,6,-9,.... 23. Solve 1^=^-2 -^^ = 0. S-x x+2 24. Prove the formula for sum of a G. P. if the first term, last term, and ratio are given. Derive formula for sum of infinite geometrical series. 25. Solve a (6 a — 13) — 2 ax (n — x) = 5(x-\- 3). 26. Why cannot a negative number have any logarithm pro- vided the base is always positive ? How are operations with negative numbers performed by aid of logarithms ? 27. Expand (2-Vx - x^^/yy. 158 GENERAL REVIEW 28. Find the values of a that will make the equation 4:X' — lox—ax-^a-{-20 = have equal roots. Prove your values correct. 29. In an A. P., Z = 14, w = 40, s = 430 ; find a and d 30. Solve 2Va;-2 + V2a; + 3 = V8a; + l. 31. From the letters in the word sweetest, how many arrange- ments can be made, taking all the letters every time ? 32. Find the middle term of (a^y — ^Vx~'^y^. 33. Solve a^ -{- xy — y^ = 1, xy-\-2y^ = 3. 34. Insert 5 geometrical means between 2| and 30f. 35. Prove the formulas for / in the progressions. Also prove the formulas for sum in arithmetical progression. 36. Solve for x, 2 V3a;-2 - 3 ^3x^-2 = 2. 37. Compute by logarithms, Y^^'^ ^ ^-^^ ^ - </.0716 X 438.6 38. Form the quadratic whose roots will be —a and ^-^ — The quadratic whose roots are -^ — ^^— — 39. Distinguish between mean proportional and third pro- portional. Find the mean and the third proportional to a and 2ab. 40. From a class of 8 boys and 10 girls, how many groups of 2 boys and 3 girls each can be selected ? 41. Solve 2^^ -3 = -^ + ^. 3x + 4: 6a;H-3 42. Insert 23 arithmetical means between 3 and 63. Also 35 means between ^ and 27.5. 43. Solve x-\-2y = 2, a^ + Sf =26. GENERAL REVIEW 159 44. Solve (x^ + x-5y-S(x^-\-x) +4:7 = 0. 45. From 16 consonants and 4 vowels, how many words can be formed, each consisting of 3 consonants and 2 vowels ? 46. Compute by logarithms the value of J -8034 x V TO gSTg ^ .5138 X ^.00175 47. A man agreed to dig a well at the rate of 25 cents for the first yard, 50 cents for the second, 7.5 cents for the third, and so on. Upon completion he received $30. How deep was the well ? 48. Find the value, by logarithms, of 2^ x (i)^ X^/^X VJ. 49. What is the value of (x - V2y + (a; + V2)* ? 50. How many figures in Q5^ ? 51. Solve a^ — a;?/ + 22/ = 4, 2x-\-3y = 5a-}-l. 52. li a:b = c: d, prove a^ -f 4 6- : c^ + 4 c?^ = a6 : cc?. 53. Prove the formulas for the number of permutations and the number of combinations of m things taken ?i at a time. 54. Form the quadratic whose roots are 0, — — . Also the one whose roots will be ^ — — — — 7 55. Solve (2 a; -3)2 -(a; -1)2 = 5. 56. Express as a polynomial, log ^ a^^/b ; log J x^s/S y. 57. Compute by logarithms, — ■T\\h7;:7:' ^ -^ ° . ' 101 ^'.SOO 58. Simplify {-y/l- o^ J^lf - {■y/l-x' -If, 59. How many combinations, each containing 6 white balls and 5 red balls, can be selected from 14 white and 10 red balls ? 60. Solve 2a^ + 3a;2/-52/2 = 4, 2a;?/ + 3/ = -3. 160 GENERAL REVIEW 61. Find x that will make 2x — l, x-^7, 3a;-f-l, in A. P. Find X if they are in G. P. 62 . Find s that will m ake the roots of 3 sor^ + 2 sa; + 9 a; + 8 = equal to each other. 63. li a : b = c : d, prove Va=* H- b' : Vc' + d' = i/a' - b^ : ^/(^-(j^. 64. Solve 8a.--3 + llVaP = 54. 65. Twenty men are going to march four abreast. In how many ways can they place themselves ? 66. Expand (V2a-Va;)®. 67. Solve y-l = x-- = -' X y 2 68. Solve 2 a^-aa;-a2 =2 (3 a; -2), for ir. 69. Find, by logarithms, the value of x, if 7^ = 100. 70. Without solving the equations, tell what is the sum, product, and character of their roots : (a) 3a^ — 7a; = — 2; (6) 5ar' + 4a; + l = 0. 71. What is the value of 2.7181818 -. ? 72. Solve 2a^-5a;-V2a^-5a; + l = l. 73. Form that quadratic the sum of whose roots is 11 and whose product is 13^. Prove your answer. 74. If a:b = b:c=c:d, prove that a-{-b:b-{-c=2 a — b:2 b—c. 75. ^o\Yeabx'-a\x-l) = b\x-\-l). 76. Find all the values of x and y in the equations (x-\-yy -x-y = Q>, x'y'^ + lxy + 12 = 0. 77. The sum of 35 terms of an A. P. is 490 and the com- mon difference is J. Find the first and last terms. GENERAL REVIEW 161 78. If m and n are the roots of ic^ — 07 + 1 = 0, show that m^-{-n^ + 1 = 0. Show that i + ^ = l. That m-n = V^^. m n 79. The sum of five terms of a G. P. is 5|^ and the ratio is |. Find the first and last terms. 80. Find the four roots of 8 a;^ = 27 x. 81. Prove that the roots of ax^ -\- 2 bx -{- c = will be equal if 6 is a mean proportional between a and c. When will the roots be rational ? 82. Expand (1 — 4 x)~^ to 5 terms. 83. Find the limit of the sum of 1 — | + ^.•. to infinity. 84. Solve4cc + 4V3a^-7a; + 3 = 3ar^-3a; + 6. 85. Find two numbers whose difference, sum, and product are to each other as 2:3:5. 86. There are three numbers in A. P. whose sum is 3. If 3, 4, and 21 be added to them, respectively, the sums form a G. P. Find the numbers. 87. How many terms of the series 32, 48, 72, •.., amount to 665? 88. Form the equation whose roots are double the roots of x'-3x-\-2^ = 0. 89. The 5th term of an A. P. is — 3 and the 15th term is 17. Find the sum of the first 20 terms. 90. How many arrangements can be made from the letters in the word holiday, taken all together ? How many, if the three letters lid are never separated ? 91. If the base of a system of logarithms be 4, tell the loga- rithm of each: 16; 8; 32; 2; J; 1; i; |; ^; Vj; </l', R. & S. EX. IN ALG. 11 162 GENERAL REVIEW 92. Solve i + i = l, 1+1 = 13. X y 0^ y^ 93. How many terms of the series 41 4, 3|, •••, amount to 21? 94. Find that G. P. the sum of an infinite number of whose terms is 4 and the second term is \. 95. Compute the 5th root of 4.281 x V.09m logarithms. 321.7 x •v/.008074 ^ 96. Find the 10th term of z^ by the binomial theorem. (l-2Va^)^ 97. Find all values of a; in 1+2 a^+3 x=3V2 a^+3 x—\. 98. If a, 6, c, dy are in continued proportion, prove that lo? + mV + ne : Ih'' -\-m&^ nd? = ac? + &c : 2 cd. 99. Solve this equation for the value of a;: a; + - = - + -. a X h 100. Find a: and ?/ in a^ + / = 3^, x-^ + 2/"^ = If 101. Find the sum of all numbers between 10 and 500 exactly divisible by 7. 102. What is meant by " completing the square " ? How is it done ? What is an imaginary ? What are conjugate im- aginaries ? Prove that log PQ = log P + log Q. 103. From the usual formulas for I and s of an A. P. derive a formula for a not containing s. A formula for I not contain- ing a. A formula for d not containing I. 104. Out of 15 consonants and 5 vowels how many words can be made each consisting of 4 consonants and 3 vowels ? 105. Find, to 3 decimal places, the logarithm of 65 in a system whose base is 15. GENERAL REVIEW 163 106. Solve Vx + y = Vy-\-2, x — y = 7. 107. When are 3 quantities in continued proportion ? Prove that if a, h, c, are in continued proportion, then a, a + b^ a + 2 6 + c, are also in continued proportion. 108. Find a; if (a^ + 2 xf -lSx(x + 2) +45 = 0. 109. If the base of a system of logarithms is a, what is log a? log-? loga^? logVa? log A/a*? logAZ-i? X y ^ a^ y^ 110. Solve ±-i: = 2, -,--, = 3i 111. Calculate by logarithms the mean proportional between V5:082 and a/.009116. 112. In a G. P. the 5th term is 12 and the 11th term is 768. Find the 3d term and sum of 9 terms. 113. Solve =l-i + i. a-^b — x a X b 114. Find a; if 2.5' = 75. 115. How many numbers, of 6 different digits each, can be written from our 9 significant digits ? 116. Find x and y if a^ — a;?/ = 1^- and xy-{-y^ = 1. 117. Insert 5 geometrical means between 5 and 3645. Also 69 arithmetical means between 5 and 3645. , , o n ^ ^1, 1 f / - 4.116 X 75.38 X .0567 \^ 118. Compute the value of ( — — , ^ ^^^. — 7:7^1^ ' ^ \S1.24: X ( - 1.909) X .0053; 11-9. Solve for x and y : x^-{-xy + 2/^ = 13 ; a^ + a^/ + 2/^ = 91. 120. Find x and y in x^ + y^-{-x-\-y = 26; ccy = — 10. ,«-. ai J? a.' — 1 -, 3a!-|-2 ^ 121. Solve for x : — 1 -!— - = 0. a; — 3 a; + 3 164 GENERAL REVIEW 122. Given log 40 = 1.60206, find log 2; log 5; log 20; log 50; log V5; log ■y/2.5', log i; log ^ ; log |; log 1.25; log 2i. 123. li S'.t = u'.v = w:x = y:Zf prove that s-\-u-\-w-\-y'.t-\-v-\-x-\-z = s:t — etc. 124. Find all* the values of a; in : 3 a^x (x + 1) (a;^ - 81) = 0. 125. Solve for x and y: x^ -\- y'^ -\- x — y = 2Q -^ xy -\-16 = 0. 126. From a delegation of 15 Protestants and 11 Catholics, there is to be chosen a committee of 6 Protestants and 4 Catho- lics. In how many ways might this be accomplished ? 127. lix^ -\-y^ = ^ and ic + ?/ = 41, find x and y. 128. If V3a;-2 + VaJ + 2 -4 = 0, find x and discuss its values as roots. 129. Given a = 2, Z = ^, s = \2^, find r and w. 130. Expand (2 - V^^)^ 131. Solve cc^ — 2/^ = 7, a; — 2/ = 133. 132. The 5th term of a G. P. is 336 and the 9th term is 5376. What is the 2d term ? 133. Finda::^±^^^^ = :^^^+1. Discuss its values. X — V12 a — x -y/a — l 134. If a certain number is divided by 8, the result will be the same as if 16 were divided by the number and 3J added to the quotient. What is the number ? 135. If V :x = x:y = y :z, prove that x-^-y is a mean pro- portional between v-\-x and y -\-z. 136. If aj + 2/4-l = a^-/ + a:2/-l = 0,finda;andy. GENERAL BEVIEW 165 137. What are the values of x in the equation ^ — ~ =4? Are these values both roots? 138. Solve x^ — 2ax — 2bx + (a + b-\-c)(a-\-b — c) = 0. 139. The sum of the first two terms of a G. P. is 72 and the sum of the next two is 8. What is the 1st term ? The 5th term ? 140. Expand to 4 terms : (y~^ — 5 a?^ —1)'^. 141. Find the series in which d = 8, 1 = 147, and s = 1425. 142. If the ratios I : m, n : p, q : r, are equal, prove that each is equal to J ''+/+/, m^ -{- p'^ -{- 7^ 143. Solve (3 a; - 2)2 4- (« - 1) = 84. 144. Prove the binomial formula for positive integral exponents. 145. What is the 7th term of (x-^ - ^Vxf)'^ ? 146. ^olYex^-\-xy-^2y^ = ll = a^-\-§y\ 147. Find a; if 2^' = 500. 148. From the figures 1, 2, 3, 4, 5, 6, 7, how many numbers can be formed of 5 different figures each ? How many of these will contain a 3 ? How many will have 3 and 6 together ? How many will be odd ? 149. Multiply .03716^ by 1.8716^ by logarithms. 150. If, in an A. P., a = s = — | and n = 20, find d and L 151. Find that G. P. whose sum to infinity is 1^ and whose 2d term is ^. 152. Solve -^ fl + J_^a; + i + l = 0. m -{- n \ mnj m n 166 GENERAL REVIEW 153. Solve - + i = -^, a;v = 54. ic 2/ 18 154. Insert 6 geometrical means between 5 and —640. 155. Find x and y if 3* 5^ = 75, 2* 7^ = 98. 156. How many different sounds can be made by striking 16 keys of a piano, 3 at a time ? 157. If 2(V^-3)2-3 = V^, find x, 158. Expand (2V3+3V2)^ 159. Find x and y from x + y = ^, x^y^ — 2^xy = — 192. 160. Solve 6a^-3a; = 2 + V2a^-a;. 161. There are two fractions the sum of whose denomina- tors is 5. The numerator of the first is the square of the de- nominator of the second, and the numerator of the second is the square of the denominator of the first. The sum of the fractions is 5|. Find them. 162. The sum of an infinite number of terms of a certain G. P. is 4i The sum of the first two terms is 2|. Find the series. 163. If log 13 = 1.1139, what is log a/1300 ? log V.0013? 164. Find a;: Va^-fl: \/2x = ^ ^ x a;-f 4 165. Evaluate the decimal 1.4363636—. 166. Solve 9a;-3x2-4Vaj2-3a;-f 5 = 0. 167. Out of 7 consonants and 4 vowels how many words can be formed, each consisting of 3 consonants and 2 vowels ? 168. Solve for x : (x-^ + i)"' = 27 and (a?"? ^ |)-i = - \. GENERAL BEVIEW 167 169. Find the numerical value of i logs 9-2 log27 3 + log, a? - log, 1. 170. Show that ma-{-nb: pa-\-qb=7nG+nd: pc-{-qd provided a, b, c, d, are proportional. 171. Find a; if 4*^-1 = (!)*-«. [Without tables.] 172. How many games must be played in a league of 10 baseball clubs, provided each club plays 10 games with every other club ? 173. Insert 5 arithmetical means between — 7 and 77. 174. Find the values of x, correct to two decimal places, in the equation ic^ — 2 a; — 2 = 0. 175. Solve iJc^ + 5xy + Sf = S, Sx^-^7 xy-{-4:y^ = 5. 176. If the series 12, 9, •••, is arithmetical, find the sum of 20 terms. If geometrical, find the sum of an infinite number of terms. 177. Solve a;^ + a;^ + 1 = 0. 178. Tell sum, product, and nature of roots of 3 a^ — 4 a; — 11 = 0. Also of 2a^ + 3ajH-7 = 0. 179. Find the sum of all the odd numbers between 20 and 220. 180. Expand (J V3 + W^-^Y and simplify. 181. If a, b, c, d, are proportional, show that ab + cd is a mean proportional between a^ + c^ and b^ + d\ 182. Solve the equations — 1--= — , a^+y^=a\ X y xy 183. Find two numbers in ratio of 7:5, the difference between whose squares is 96. 168 GENERAL. BEVIEW 3/ = 184. Find the 8th term of the expansion of va — 6Vaa;, by the binomial theorem. 185. Solvefor?/: l+V8^-32/2 = 22/. 186. Solve a; 4- 2/ + 2 Va; + 2/ = 24, « - ?/ + 3 Va; — 2/ = 10. 187. Find the value oiz: o?z-2h^= ah 188. Solve? + - = 5, ^, + -^-^ = -19. X y x- xy y^ Hint: Let- = w, - = w.1 L X y A 189. Discuss the values of x in the equation, V3a; + 1 = V9aj + 4 - V2 a; - 1. 190. Find, by logarithms, the values of x and y^ if 3"= = 50 ^ and 2^ = b y. 191. Find the (r + l)th term of (1 - x)^. 192. Simplify (2 - Vl - xy + (2 + Vl - x)\ 193. Compute, by logarithms, the value of ^moiW^- 194. Solve Va — a; + V— (a^ + ax) = -^= X 195. If a, 6, and c are in G. P., show that , -, and aremA.P. « + *2' 6 + <= 196. Find the 3 cube roots of unity ; i.e. solve the equa- tion x^ = 1. GENERAL BEVIEW 169 197. Solve for x:-\ h - ^ = ^^, — 7^ — 2 I 1 — a x\ x(a- — 1) 198. Solve V5a; + l + 2Vaj-2 = 3V2(a;-l). 199. Solve (m + xy — (m — xy = x. 200. Of how many terms does an A. P. consist in which d = 'S, 1 = 302, a = 5? 201. The sum of an infinite number of terms of a G-. P. is 15 and the second term is 3^. Find the fourth term. 202. Solve ^-^ = ^. a^ - 1 x' + l 20 203. Expand (V2«— ^3»)*. 204. The difference between two numbers is 32 and the arithmetical mean exceeds the geometrical mean by 4. Find the numbers. 205. By the principles of proportion find x if Va; + 2 - Va; - 3 ^ Vr) .c + 1 - 4 V.t - 6 ■y/x + 2 + ^x^^ V5a.- + l + 4Va;-6 206. Find sum of i — 1 — f ••• to 29 terms. 207. Find sum of 1 + J + !••• to 6 terms. 208. Solve aV — oi^ — d^x — 5ax = 6a^. 209. The sum of 10 terms of an A. P. is 100 and the sixth term is 11. Find the second term. 210. Solve a^_a; + l + -_-l =^. ar — a^ + 1 3 170 GENERAL REVIEW 211. The sides of a right triangle are in A. P. Prove that they are proportional to 3, 4, 5. 212. Find a; if 213. How many terms of the series IJ, 1, |, •••, must be taken, that the sum may be zero ? 214. Solve 2a^-3x + 4 = -— -4 ^• 2x'-Sx + 2 215. In an A. P. a = 7, d = — i s = 55. Find n and Z. 216. If V<x + a; : Va + Va + x = Va — a; : Va — Va — x, find a;. Solve the following simultaneous quadratic equations and associate the corresponding values of x and y: 217. y^ + xy-^y = -6', x'-\-xy-^x = S, 218. x(x -h 2/) = 10 ; 2/(2/ - x) = 3. 219. VaH^— Va; — 2/ = 2; 3aj-22/ = 7. 220. 3,-3-1 = 316; a;-i=4. r y 221. a^ + 2 a^ = - 21 ; y^ ■^2xy=-b. 222. «2 + 2/2_4aVa^ 4- 2/^ = 5^2; y? - f :=! a\ 223. a(a; — a) = 6(2/ — 6) ; ax -{- by = xy. 224. 6a^y^ + 5xy = 6; x -\- SO y = 12. o«, i (^-32/)^-8a; + 24^ = -12; ''^^' ^2(2a; + 2/)2-22a;-lli/ = ^5. GENERAL REVIEW 171 226. x-y-^x — y = 2; a?-f = 20^. 227. 2:f?-xy = \2', a? -2 xy + Zy'' = ^. 228. ^x^-{-6xy — 3x — y + 2 = 0'^ 2x-\-5y= — 4:. 229. One root of the equation a^ — 6ic+29=0is 3— 2V^^. Without solving this quadratic, find the other root and prove your answer correct. 230. Solve: ^- ^=2£l^. a;— 1 aj-f-l a^ — 2a 231. Find the limit of the sum of the series 5 — 3 + 1 — ^ + ^ — • • • to infinity. 232. Solve: V3a^-2a; + 4 = 3 0.-2-23;- 8. 233. If w, X, y, and z are proportional, show that -\/w^ — y^y Vor — z^, w-\- y, X + z, are also proportional. 234. Find the ninth term of (ia^y-2 ^/xy\ 235. Divide 9 J into three parts in G. P. such that the sum of the first two is to the sum of the last two as 3 to 2. 236. For what values of m will the equation 4 ic^ — 15 ic + 36 = m(x — 1) have equal roots ? Verify your results. 172 LOGARITHMS No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 0000 0414 0792 1139 1461 0043 0453 0828 1173 1492 0086 0492 0864 1206 1523 0128 0531 0899 1239 1553 0170 0569 0934 1271 1584 0212 0607 0969 1303 1614 0263 0645 1004 1336 1644 0294 0682 1038 1367 1673 0334 0719 1072 1399 1703 0374 0766 1106 1430 1732 15 16 17 18 19 1761 2041 2304 2553 2788 1790 2068 2330 2577 2810 1818 2095 2355 2601 2833 1847 2122 2380 2625 2856 1875 2148 2405 2648 2878 1903 2175 2430 2672 2900 1931 2201 2465 2696 2923 1969 2227 2480 2718 2945 1987 2263 2604 2742 2967 2014 2279 2629 2766 2989 20 21 22 23 24 3010 3222 3424 3617 3802 3032 3243 3444 3636 3820 3054 3263 3464 8655 3838 3075 3284 3483 3674 3856 3096 3304 3502 3692 3874 3118 3324 3522 3711 3892 3139 3345 3541 3729 3909 3160 3365 3560 3747 3927 3181 3385 3579 3766 3945 3201 3404 3698 3784 3962 25 26 27 28 29 3979 4150 4314 4472 4624 3997 4166 4330 4487 4639 4014 4183 4346 4502 4654 4031 4200 4362 4518 4669 4048 4216 4378 4533 4683 4065 4232 4393 4648 4698 4082 4249 4409 4664 4713 4099 4265 4425 4579 4728 4116 4281 4440 4594 4742 4133 4298 4456 4609 4767 30 31 32 33 34 4771 4914 5051 5185 5315 4786 4928 5065 5198 5328 4800 4942 5079 5211 5340 4814 4955 5092 5224 5353 4829 4969 6105 5237 5366 4843 4983 5119 5250 5378 4857 4997 6132 5263 6391 4871 5011 6145 5276 6403 4886 6024 6169 6289 6416 4900 5038 5172 5302 6428 35 36 37 38 39 5441 5563 5682 5798 5911 5453 5575 5694 5809 5922 5465 5587 5705 5821 5933 5478 5599 5717 5832 5944 5490 5611 5729 5843 5955 5502 5623 6740 6865 6966 5614 5635 6752 5866 6977 5527 5647 6763 5877 6988 6539 5658 6776 6888 6999 6551 5670 6786 6899 6010 40 41 42 43 44 6021 6128 6232 6335 6435 6031 6138 6243 6345 6444 6042 6149 6253 6355 6454 6053 6160 6263 6365 6464 6064 6170 6274 6375 6474 6076 6180 6284 6385 6484 6086 6191 6294 6395 6493 6096 6201 6304 6406 6503 6107 6212 6314 6415 6513 6117 6222 6325 6425 6522 45 46 47 48 49 6532 6628 6721 6812 6902 6542 6637 6730 6821 6911 6551 6646 6739 6830 6920 6561 6656 6749 6839 6928 6571 6665 6758 6848 6937 6580 6676 6767 6857 6946 (5590 6684 6776 6866 6955 6599 6693 6785 6876 6964 6609 6702 6794 6884 6972 6618 6712 6803 6893 6981 50 51 52 53 54 6990 7076 7160 7243 7324 6998 7084 7168 7251 7332 7007 7093 7177 7259 7340 7016 7101 7185 7267 7348 7024 7110 7193 7275 7366 7033 7118 7202 7284 7364 7042 7126 7210 7292 7372 7050 7135 7218 7300 7380 7059 7143 7226 7308 7388 7067 7152 7235 7316 7396 LOGARITHMS 173 No. 1 2 3 4 5 6 7 8 9 55 56 67 58 59 7404 7482 7559 7634 7709 7412 7490 7566 7642 7716 7419 7497 7574 7649 7723 7427 7505 7582 7657 7731 7435 7513 7589 7664 7738 7443 7520 7597 7672 7745 7451 7528 7604 7679 7752 7459 7536 7612 7686 7760 7466 7543 7619 7694 7767 7474 7551 7627 7701 7774 60 61 62 63 64 7782 7853 7924 7993 8062 7789 7860 7931 8000 8069 7796 7868 7938 8007 8075 7803 7875 7945 8014 8082 7810 7882 7952 8021 8089 7818 7889 7959 8028 8096 7825 7896 7966 8035 8102 7832 7903 7973 8041 8109 7839 7910 7980 8048 8116 7846 7917 7987 8055 8122 65 66 67 68 69 8129 8195 8261 8325 8388 8136 8202 82(57 8331 8395 8142 8209 8274 8338 8401 8149 8215 8280 8344 »407 8156 8222 8287 8351 8414 8162 8228 8293 8357 8420 8109 8235 8299 8363 8426 8176 8241 8306 8370 8432 8182 8248 8312 8376 8439 8189 8254 8319 8382 8445 70 71 72 73 74 8451 8513 8573 8633 8692 8457 8519 8579 8639 8698 8463 8525 8585 8645 8704 8470 8531 8591 8651 8710 8476 8537 8597 8657 8716 8482 8543 8603 8663 8722 8488 8549 8609 8669 8727 8494 8555 8615 8675 8733 8500 8561 8621 8681 8739 8506 8567 8627 8686 8745 75 76 77 78 79 8751 8808 8865 8921 8976 8756 8814 8871 8927 8982 8762 8820 8876 8932 8987 8768 8825 8882 8938 8993 8774 8831 8887 8943 8998 8779 8837 8893 8949 9004 8785 8842 8899 8954 9009 8791 8848 8904 8960 9015 8797 8854 8910 8965 9020 8802 8859 8915 8971 9025 80 81 82 83 84 9031 9085 9138 9191 9243 9036 9090 9143 9196 9248 9042 9096 9149 9201 9253 9047 9101 9154 9206 9258 9053 9106 9159 9212 9263 9058 9112 9165 9217 9269 9063 9117 9170 9222 9274 9069 9122 9175 9227 9279 9074 9128 9180 9232 9284 9079 9133 9186 9238 9289 85 86 87 88 89 9294 9345 9395 9445 9494 9299 9350 9100 9450 9499 9304 9355 9405 9455 9504 9309 9360 9410 9460 9509 9315 9365 9415 9405 9513 9320 9370 9420 9469 9518 9325 9375 9425 9474 9523 9330 9380 9430 9479 9528 9335 9385 9435 9484 9533 9340 9390 9440 9489 9538 90 91 92 93 94 9542 9590 9638 9685 9731 9547 9595 9643 9689 9736 9552 9600 9647 9694 9741 9557 9605 9652 9699 9745 9562 9609 9657 9703 9750 9566 9614 9661 9708 9754 9571 9619 9666 9713 9759 9576 9624 9671 9717 9763 9581 9628 9675 9722 9768 9586 9633 9680 9727 9773 95 96 97 98 99 9777 9823 9868 9912 9956 9782 9827 9872 9917 9961 9786 9832 9877 9921 9965 9791 983(3 9881 9926 9969 9795 9841 9886 9930 9974 9800 9845 9890 9934 9978 9805 9850 9894 9939 9983 9809 9854 9899 9943 9987 9814 9859 9903 9948 9991 9818 9863 9908 9952 9996 Phillips and Fisher's Geometry By ANDREW W. PHILLIPS, Ph.D. and IRVING FISHER, Ph.D. Yale University PHILLIPS AND FISHER'S ELEMENTS OF PLANE AND SOLID GEOMETRY $1.75 PHILLIPS AND FISHER'S PLANE AND SOLID GEOMETRY. Abridged $1.25 PHILLIPS AND FISHER'S PLANE GEOMETRY— Separate . 80 cents PHILLIPS AND FISHER'S GEOMETRY OF SPACE— Separate $1.25 PHILLIPS AND FISHER'S LOGARITHMS OF NUMBERS . 30 cents The publication of this text-book marks a new era in the teaching of Geometry. Its distinctive qualities are : (i) clearness of presentation, both in form of statement and in the diagrams ; (2) natural and sym- metrical methods of proof ; (3) abundance and variety of original problems for demonstration and for numerical computation. But the feature which more than any other distinguishes it from similar text-books is the use of photo-engravings of geometrical figures arranged side by side with skeleton drawings of the same, whereby the most magnificent collection of geometrical models ever constructed is brought within reach of every preparatory school and college student. By this method of illustration the great problem of educating the student's imagination to a proper comprehension of the figures of solid geometry is practically solved. The Abridged Edition is intended for those schools which desire a briefer course than that offered in the complete work. It has all the excellencies and features of the larger book, including the reproductions of the models. Copies of any of these books sent, prepaid, on receipt of price. American Book Company New York ♦ Cincinnati ♦ Chicago (69) Lessons in Physical Geography By CHARLES R. DRYER, M.A., F.G.S.A. Professor of Geography in the Indiana State Normal School Half leather, 12mo. Illustrated. 430 pages. . . , Price, $1.20 EASY AS WELL AS FULL AND ACCURATE One of the chief merits of this text-book is that it is simpler than any other complete and accurate treatise on the subject now before the public. The treatment, although specially adapted for the high school course, is easily within the comprehension of pupils in the upper grade of the grammar school. TREATMENT BY TYPE FORMS The physical features of the earth are grouped according to their causal relations and their functions. The characteristics of each group are presented by means of a typical example which is described in unusual detail, so that the pupil has a relatively minute knowledge of the type form. INDUCTIVE GENERALIZATIONS Only after the detailed discussion of a t5rpe form has given the pupil a clear and vivid concept of that form are explanations and general prin- ciples introduced. Generalizations developed thus inductively rest upon an adequate foundation in the mind of the pupil, and hence cannot appear to him mere formulae of words, as is too often the case. REALISTIC EXERCISES Throughout the book are many realistic exercises which include both field and laboratory work. In the field, the student is taught to observe those physiographic forces which may be acting, even on a small scale, in his own immediate vicinity. Appendices (with illustrations) give full instructions as to laboratory material and appliances for observation and for teaching. SPECIAL ATTENTION TO SUBJECTS OF HUMAN INTEREST While due prominence is given to recent developments in the study, this does not exclude any link in the chain which connects the face of the earth with man. The chapters upon life contain a fuller and more adequate treatment of the controls exerted by geographical conditions upon plants, animals, and man than has been given in any other similar book. MAPS AND ILLUSTRATIONS The book is profusely illustrated by more than 350 maps, diagrams, and reproductions of photographs, but illustrations have been used only \yhere they afford real aid in the elucidation of the text. Copies sent, prepaid, on receipt of price, American Book Company New York ♦ Cincinnati ♦ Chicago (112) Bim™w^ 14 DAY USE MTO«N TO DESK FROM WHI^I BORRO^^o LOAN OEPT Renewed books are subierf »o .„ !■ "»resuo,ect to immediate recaU. retrtrb VUui^ '~^^imis« (A9562slb)476B^ fT .^^*"."al Library Umyersity of California Berkeley <AfL /« ^, <^. 9/ f^ f-^ <a^^ THE UNIVERSITY OF CAUFORNIA UBRARY k