Writing a Function Rule ALGEBRA 1 LESSON 5-4 pages 256–259  Exercises 1. B 2. A 3. C 4. ƒ(x) = 3x 5. ƒ(x) = x – 0.5 6. ƒ(x) = 0.5x 7. ƒ(x) = –3x 8. y = 4x 9. y = x 2 10. t(c) = 0.79c 11. d(n) = 45n 12. ƒ(h) = h 13. e(n) = 6.37n 14. A(n) = n2 15. V(n) = n3 16. A(r) = r 2 17. a.ƒ(x) = 0.19x b. $1.52 18. a. ƒ(x) = 0.34 + 0.21(x – 1) b. $.97 19. ƒ(x) = 1000x 20. ƒ(x) = 2.54x 1 12 21. a. C(a) = 10a + 1 b. $31 c. 61; the total cost of 12 books 22. a. C(b) = 6b b. 72; the total cost of c. about $5.08 d. Club; $61 is less than $72. 23. Answers may vary. Sample: The input values you need may not be in the table. 5-4

Writing a Function Rule ALGEBRA 1 LESSON 5-4 24. a. gal of water, number of loads b. w(n) = 34n c. 238 gal d. 13 loads 25–28. Tables may vary. Samples are given. 25. ƒ(x) = x 26. y = x + 3 27. y = –x + 2 28. y = x 29. Answers may vary. Sample: ƒ(x) = 60x; ƒ(3) = 180, 180 mi in 3 h, the distance you can travel at a constant speed of 60 mi/h 30. a. 0.15b b. c(b) = 1.15b c. $20.70 31. ƒ(x) = x3 32. ƒ(x) = –x3 33. ƒ(x) = –x3 – 1 34. a. c(m) = 44 + 0.38m b. $70.60, $89.60 c. 38 mi d. $202 3 2 1 2 2 3 5-4

Writing a Function Rule ALGEBRA 1 LESSON 5-4 35. a. B(v) = 6.93v b. B(w) = w 36. A 37. H 38. D 39. B 40. C 41. [2] D = 0.1w 2 + 5w D = 0.1(60)2 + 5(60) D = 0.1(3600) + 300 D = 660   The dosage is 660 mg. [1] correctly substitutes 60 for w but makes a minor calculation error 42–47. Tables may vary. Samples are given. 42. 43. 7 10 5-4

Writing a Function Rule ALGEBRA 1 LESSON 5-4 44. 45. 46. 47. 48. 17%; increase 49. 2%; increase 50. 8%; decrease 51. 83%; decrease 52. 29%; increase 53. 42%; decrease 54. a. 2 oranges; 3 oranges b. 28 tbsp 5-4