31.) Katie was walking down a rocky path. For 4 minutes, the elevation dropped uniformly. Altogether it dropped 8 feet. What was the CHANGE IN ELEVATION PER minute for the 4 minutes? 32.) As a front passed, the temperature changed steadily over 6 hours. Altogether it changed -18 degrees. What was the CHANGE IN TEMPERATURE PER hour for the 6 hours? 33.) The Dolphins football team gained 16 yards on their first play then lost 11 yards on the next play. Write an addition expression to represent this situation. Find the sum. 34.) Hunter deposits $120 into his account. One week later, he withdraws $36. Write an addition expression to represent this situation. How much higher or lower is the amount in his account after these two transactions? 35.) A roller coaster begins at 90 feet above ground level. Then it descends 105 feet. Find the height of the coaster after the first descent