Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 pages 380–384  Exercises 1. no 2. yes 3. no 4. 5. 9. 10. 11. 6. 7. 8. 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 16. x > 5 and y –x + 3 17. y – x – 2 and y x + 2 18. y – x + 1 and y – x + 3 19. y – x – 4 and y x – 3 20. a. 1.5f + 2.5c < 9.50, f + c > 4 b. 21. 12. 13. 14. 15. > – 22. a. 5.99x + 9.99y 50, x 0, y 1 b. c. 2 books and 6 CDs; no, (2, 6) is not in the shaded region. d. Answers may vary. Sample: 3 books and 3 CDs for $47.94 < – 1 2 1 2 > – > – > – < – 1 5 3 4 > – > – 2 3 1 5 < – > – 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 25. x 3, x –3, y 3, y –3 26. y 2, x < 5, y x 27. y x – 2, y < x + 2 28. y –x – 3, y –x + 3, y x + 3, y x – 3 29. Answers may vary. Sample: x –2, x 4, y 1, y –2 30. a. –1      b. 8 31. a. triangle      b. (2, 2), (–4, –1), (–4, 2)      c. 9 units2 23. x + y 30, 1.25x + 3y 60 24. a. x + y 12, 6x + 4y 60 b. Answers may vary. Sample: (8, 3), (9, 1), (10, 0) > – < – < – > – < – > – > – < – 2 3 2 3 > – > – < – < – > – > – < – > – < – < – > – 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 32. a. square b. (1, –1), (5, –1), (1, 3), (5, 3) c. 16 units2 33. a. trapezoid b. (0, –4), (0, 2), (2, –4), (2, 0) c. 10 units2 34. a. triangle b. (2, –3), (2, 2), (7, –3) c. 12.5 units2 35. a. x 1, 10.99x + 4.99y 45 b. (3, 0), (3, 1), (3, 2), (4, 0) 36. a. b. No; they are parallel. c. no d. no 37. a. c. It is a strip between the lines. > – < – 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 38–42. Answers may vary. Samples are given. 38. x 1 and y 2 39. x < 0 and y > 0 40. y > 5 and y < 3 41. x < 2 and y < 5 42. x > 0 and y < 0 43. a. s + d > 10, s + d < 20, d 3, 10d + 0.15s < 60 b. Answers may vary. Sample: (8, 4.5); 12.5g; gold: $45.00, silver: $1.20 44. 45. Answers may vary. y > x, y < 2x 46. Answers may vary. y > x + 1, y > –x + 1 47. a. h 2 + 0.400a b. c. Answers may vary. Sample: 5 hits, 6 at-bats < – < – 1 2 > – > – 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 48. a. 180x + 240y 2700 x + y 17 x > y y 4 b. Answers may vary. Sample: ten 14-in. drums and six 18-in. drums 49. D 50. G 51. [2] all points on the line 3x + 4y = 12 [1] incorrect description given > – 52. [4] a. Let x = number of toppings, and y = cost of pizza. Maria’s: y = 0.50x + 8 Tony’s: y = 0.75x + 7 b. (4, 10)  With 4 toppings, the cost is $10 at either Tony’s or Maria’s. c. Answers may vary. Sample: Since I prefer more than 4 toppings, I will go to Maria’s, because the pizza will be less expensive. [3] (a) and (b) only done correctly [2] (a) done correctly, but student makes a computational error in (b) [1] error in (a), but system solved correctly < – > – 7-6

Systems of Linear Inequalities ALGEBRA 1 LESSON 7-6 59. 60. –3 61. –8 62. – 63. – 64. – 65. 66. 67. 68. ƒ(x) = 7x 69. ƒ(x) = x + 6 70. ƒ(x) = x 2 5 2 53. 54. 55. 56. 57. 58. 1 4 1 5 8 3 10 9 6 13 15 4 7-6