1 (+9) - (+4)

2 -7 - (+5)

3 -10 - (-4)

4 3 - (-8)

5 -7 - (-12)

6 -15 - 15

7 13 - (-13)

8 0 - 6

9 0 - (-5)

10 -2 - 5 - (-7) - 3 - (-4)

11 A - (-A)

12 N - N

13 -K - K

14 (5 - 7) - (7 - 5)

15

16

17 16 - {7-(-2)}

18 -(8 - 3) - (3 - 6)

19

20 27 - (-0)

21 0 - (-5)

22 -23 - [-(-13) - 5] - (-2)

23 X - Y

24 Y - Z

25 X - (-Z)

26 -(X) - (-Y)

27 X - Y + Z

28

29

30 -3 - 5

31 -(3 - 4 - 5)

32 (-10) - 10

33 -6 - (-4)

34 0 - (-5)

35

36 Two summers ago the depth of Spada lake at a test point was 123 feet. Last winter, due to snow melt it increased in depth by 38 feet. Due to the last dry summer it dropped 19 feet. What is its current depth?

37 The temperature in the morning at the peak of Mt. Rainier was -10° C, and was 17° C in the afternoon. What was the change in temperature from morning to afternoon?

38 A bungee jumper had an unstretched bungee cord of 120 ft. At the bottom of the jump the line stretches 32 ft. If the height from the bridge to the river is 157 ft., and the jumper is 6 ft. tall, where is the top of her head relative to the surface of the water