Step-by-step explanation:
a. The expression that represents the number of cans in each case that is missing cans is: 4c - 20 (where c represents the number of cans in a full case).
b. The equation to find c is: 16c + 4(4c - 20) = 220
c. Solving for c:
16c + 16c - 80 = 220
32c - 80 = 220
32c = 300
c = 9.375
So, there are 9.375 cans in a full case, and each of the 4 other cases is missing 5 cans, making it 9.375 - 5 = 4.375 cans in each of those cases.