Basic Technical Mathematics, 11th Edition

Exercises 1.2, page 10

1. 1. 20

2. 3. $\hspace{0.17em}-\hspace{0.17em}4$

3. 5. $\hspace{0.17em}-\hspace{0.17em}3$

4. 7. 6

5. 9. $\hspace{0.17em}-\hspace{0.17em}3$

6. 11. $\hspace{0.17em}-\hspace{0.17em}28$

7. 13. 35

8. 15. 20

9. 17. 40

10. 19. $\hspace{0.17em}-\hspace{0.17em}1$

11. 21. $\hspace{0.17em}-\hspace{0.17em}32$

12. 23. $\hspace{0.17em}-\hspace{0.17em}17$

13. 25. Undefined

14. 27. 20

15. 29. 16

16. 31. $\hspace{0.17em}-\hspace{0.17em}6$

17. 33. $\hspace{0.17em}-\hspace{0.17em}24$

18. 35. $\hspace{0.17em}-\hspace{0.17em}6$

19. 37. $\hspace{0.17em}-\hspace{0.17em}1$

20. 39. Commutative law of multiplication

21. 41. Distributive law

22. 43. Associative law of addition

23. 45. Associative law of multiplication

24. 47. d

25. 49. b

26. 51. $\hspace{0.17em}=\hspace{0.17em}$

27. 53.

    1. Positive 

    2. Negative

28. 55. Correct. (For $x\hspace{0.17em}>\hspace{0.17em}0\hspace{0.17em},\hspace{0.17em}x$ is positive; for $x\hspace{0.17em}<\hspace{0.17em}0\hspace{0.17em},\hspace{0.17em}\hspace{0.17em}-\hspace{0.17em}x$ is positive.)

29. 57.

    1. Negative reciprocals of each other

    2. They may not be equal.

30. 59. $\hspace{0.17em}-\hspace{0.17em}0.29$

31. 61. $\hspace{0.17em}-\hspace{0.17em}2.4\text{ kW}\hspace{0.17em}\cdot \hspace{0.17em}\text{h}$

32. 63. $\hspace{0.17em}-\hspace{0.17em}2\hspace{0.17em}°\hspace{0.17em}\text{C}$

33. 65. 10 V

34. 67. $100\text{m }\hspace{0.17em}+\hspace{0.17em}200\text{m }\hspace{0.17em}=\hspace{0.17em}200\text{m }\hspace{0.17em}+\hspace{0.17em}100\text{m}\hspace{0.17em};\hspace{0.17em}$ commutative law of addition

35. 69. $7(25\text{min }\hspace{0.17em}+\hspace{0.17em}15\text{min})\hspace{0.17em};\hspace{0.17em}$ distributive law