101 38. (Modeling) Online College Courses The number of students (in millions) taking at least one online college course between the years 2012 and 2016 can be approximated by the formula Number of students = 0.0336x2 + 0.0807x + 5.43, where x = 0 corresponds to 2012, x = 1 corresponds to 2013, and so on. According to this model, how many students took at least one online college course in 2016? Round the answer to the nearest tenth of a million. (Data from U.S. Department of Education.) Evaluate each expression. 39. -6 + 14 + 1-112 - 1-32 40. 10 - 4 # 3 + 61-42 41. 1-4 - 121-3 - 52 - 23 42. 16 - 921-2 - 72 , 1-42 43. a- 5 9 - 2 3b - 5 6 44. a- 23 5 - 3 4b - a- 1 2b 45. 61-42 - 321-223 -53-2 - 1-624 46. 1-721-32 - 1-2321-52 1-22 - 221-1 - 62 Evaluate each expression for a = -1, b = -2, and c = 4. 47. -c12a - 5b2 48. 1a - 22 , 5 # b + c 49. 9a + 2b a + b + c 50. 30 b0 - 40 c 0 0 ac 0 Simplify each expression. Write answers without negative exponents. Assume all variables represent positive real numbers. 51. a- 5 4b -2 52. 3-1 - 4-1 53. 15z321-2z52 54. 18p2q321-2p5q-42 55. 1-6p5w4m1220 56. 1-6x2y-3z22-2 57. -8y7p-2 y-4p-3 58. a-61a-82 a-21a112 59. 1p + q241p + q2-3 1p + q26 60. 3p21m+ n234-2 p-21m+ n2-5 61. 17r1/2212r3/421-r1/62 62. 1a3/4b2/321a5/8b-5/62 63. y5/3 # y-2 y-5/6 64. a 25m3n5 m-2n6 b -1/2 65. 1p15q122-4/3 1p24q162-3/4 66. Simplify the product -m3/418m1/2 + 4m-3/22. Assume the variable represents a positive real number. Perform the indicated operations. 67. 13q3 - 9q2 + 62 + 14q3 - 8q + 32 68. 213y6 - 9y2 + 2y2 - 15y6 - 4y2 69. 18y - 7212y2 + 7y - 32 70. 12r + 11s214r - 9s2 71. 13k - 5m22 72. 14a - 3b22 Perform each division. 73. 4a5 - 4a2 + 8 -4a 74. 20a4b3 - 15a5b2 + 25a3b 5a4b3 75. 30m3 - 9m2 + 22m+ 5 5m+ 1 76. 72r2 + 59r + 12 8r + 3 77. 3b3 - 8b2 + 12b - 30 b2 + 4 78. 5m3 - 7m2 + 14 m2 - 2 CHAPTER R Review Exercises
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