Factoring by Grouping pages 499–501 Exercises ALGEBRA 1 LESSON 9-8 pages 499–501 Exercises 1. 2m2; 3 2. 5p2; 2 3. 2z2; –5 4. 3n2; 1 5. (2n2 + 1)(3n + 4) 6. (7t 2 + 8)(2t + 3) 7. (3t + 1)(3t – 1)(3t + 5) 8. (y2 + 1)(13y – 8) 9. (5x2 + 1)(9x + 4) 10. (2w2 – 3)(5w + 8) 11. 2(2v2 + 1)(3v – 8) 12. q(q 2 + 4)(7q – 4) 13. 2(m2 + 2)(10m – 9) 14. 2x(x + 1)(x – 1)(3x + 2) 15. 2(2y2 + 5)(3y – 5) 16. 3(c2 + 2)(3c – 4) 17. (6p + 5)(2p + 1) 18. (4t + 3)2 19. (6n – 1)(3n + 10) 20. (3w – 5)(3w – 4) 21. 2(6m – 1)(2m + 1) 22. (12v – 7)(3v + 1) 23. (3x – 2)(2x + 5) 24. (4v – 1)(5v – 9) 25. (7q + 2)(9q – 10) 26. m, (3m + 1), and (m + 2) 27. 5k, (k + 2), and (k + 4) 28. 7h(h – 6)(h + 1) 29. 2(10t 2 – 11)(3t – 10) 30. 8(d 2 + 3)(d + 2) 31. 4(3x – 7y)(x + 2y) 32. 9r (3r – 1)(2r – 1) 33. 10(5k2 + 6)(3k + 7) 34. a. (7x2 + 9)(4x – 1) b. (4x – 1)(7x2 + 9) c. Answers may vary. Sample: The factorings are equivalent; but the factors may appear in a different order. 9-8
40. Answers may vary. Sample: 30x2 + 36x + 40x + 48; 2(3x + 4)(5x + 6) Factoring by Grouping ALGEBRA 1 LESSON 9-8 35. (7w 2 – 4)(2w + 7) 36. (2m2 – 1)(m – 16) 37. 2(2t 2 + 3)(11t – 1) 38. (x2 – 2)(25x – 1) 39. 2w, (6w + 5), and (7w + 1) 40. Answers may vary. Sample: 30x2 + 36x + 40x + 48; 2(3x + 4)(5x + 6) 41. Answers may vary. Sample: Split the expression into two groups. Remove the GCF from each group, and then factor again. 42. (6m3 – 7n2)(5m2 + 4n) 43. (x2 + y)(p + q5) 44. (h + 2)(h – 2)(h + 11) 45. (w 2 + 3)(w 2 – 3)(w + 1)(w – 1) 46. a. 2 x(x + 3)2 b. x + 3 47. (23 + 20)(22 + 21 + 20); (9)(7) 48. (24 + 22 + 20) (21 + 20); (21)(3) 49. Answers may vary. Samples are given. a. length = 2x + 4; width = x; height = x + 4 b. 2x3 + 12x2 + 16x 50. C 51. H 52. [2] 9a4 – 54a3 – 2a + 12 = 9a3(a – 6) – 2(a – 6) = (9a3 – 2)(a – 6) [1] appropriate methods with one computational error 9-8
solutions on the line y = –4x+ 25 84. (7, 2) Factoring by Grouping ALGEBRA 1 LESSON 9-8 58. (m + 8)(m – 8) 59. 4(g + 5)2 60. (2d + 5)(2d – 5) 61. 5(n + 3)(n – 3) 62. (5q + 4)2 63. b4 64. x2 65. t 15 66. c35d 7 67. 8y3 68. 1 69. 70. 81w8v12 71. 1.6 1021 1 x11 72. 9 1012 73. 4.9 10–11 74. 3.2 1036 75. 2.809 105 76. 6.561 10–5 77. 6.859 1024 78. 6.25 104 79. (1, 5) 80. (4, –8) 81. (0.5, 5) 82. (2, –30) 83. infinitely many solutions on the line y = –4x+ 25 84. (7, 2) 53. [4] 96x3 + 48x2 + 6x = 6x(16x2 + 8x + 1) = 6x(4x + 1)2. Side of square equals 4x + 1. Perimeter = 4(4x + 1) = 16x + 4. [3] appropriate methods, but with one computational error [2] found factors of polynomial, but did not find perimeter [1] correct answer, without work shown 54. (k + 7)2 55. (r + 3)2 56. (y – 8)2 57. 2(t + 3)2 9-8