Quadratic Equations Answers

1. x = -2 or x = 5

 21. x = 2.91 or x = 0.09

2. x = 9 or x = -9

 22. x = 0.38 or x = 2.62

3. s = 4 or s = 8

 23. b = -7

4. p = 1 or p = -16

 24. x = 5.24 or x = 0.76

5. r = 3 or r = -4

 25. d = 4 or d = -4

6. y = 0 or y = 1.25

 26. y = 9 or y = -2/3

7. x = 0 or x = 8

 27. x = 3.35 or x = 0.15
8. x = 6 or x = 12 28. y = 0 or y = 6

9.a = 11 or a = -11

 29. t = 1 or t = 6

10. x = 0.5 or x = -0.5

 30. q =1.16 or -1.29 (to 3 sig.figs.)

11. x = 4 or x = -3

 31. x = -2 or x = 10

12. y = 5

 32. r = 0.30 or r = -3.30

13. r = -2.5 or r = 2/3

 33. Length = 60 m and width = 40 m

14. s = 0.75 or s = 0.2

 34. Width of car park is 80 metres, length is 90 m

15. t = 1/3 or t = -1

 35. Length is 15 cm and width is 10 cm
16. x = -10 or x = 0 36. Janice is 32 years old
17. p = -0.39 or p = -7.61 37. base = 3.71 cm and height = 4.71 cm
18. s = 6.37 or s = 0.63 38. The numbers are 45 and 47
19. y = -2.83 or y = 0.83 39. The sides are 4.1 cm and 6.1 cm (to 2sf)
20. x = -0.13 or x = -1.87 40. x = 7.9 cm (to 2 sf)