Solutions to Try Its

1. 11 and 25

2. $C=2.5x+3,650$

3. 45 mi/h

4. $L=37$ cm, $W=18$ cm

5. 250 ft²

Solutions to Odd-Numbered Exercises

1. Answers may vary. Possible answers: We should define in words what our variable is representing. We should declare the variable. A heading.

3. $2,000-x$

5. $v+10$

7. Ann: $23$; Beth: $46$

9. $20+0.05m$

11. 300 min

13. $90+40P$

15. 6 devices

17. $50,000-x$

19. 4 h

21. She traveled for 2 h at 20 mi/h, or 40 miles.

23. $5,000 at 8% and $15,000 at 12%

25. $B=100+.05x$

27. Plan A

29. $R=9$

31. $r=\frac{4}{5}$ or 0.8

33. $W=\frac{P - 2L}{2}=\frac{58 - 2\left(15\right)}{2}=14$

35. $f=\frac{pq}{p+q}=\frac{8\left(13\right)}{8+13}=\frac{104}{21}$

37. $m=\frac{-5}{4}$

39. $h=\frac{2A}{{b}_{1}+{b}_{2}}$

41. length = 360 ft; width = 160 ft

43. 405 mi

45. $A=88\text{ in}{.}^{2}$

47. 28.7

49. $h=\frac{V}{\pi {r}^{2}}$

51. $r=\sqrt{\frac{V}{\pi h}}$

53. $C=12\pi$