Answer:
The costs per year U(x) and S(x) when x represents the number of fitness classes attended:
1) U(x) = 250 + 3.5 * x
2) S(x) = 400 + 2 * x
3) Set the costs of both gyms to be equal and solve for x:
U(x) = S(x)
250 + 3.5 * x = 400 + 2 * x
1.5 * x = 150
x = 100
The costs for both fitness gyms are the same when you attend 100 classes. The costs are:
U(100) = 250 + 3.5 * 100 = 250 + 350 = 600
S(100) = 400 + 2 * 100 = 400 + 200 = 600
Both gyms will cost $600 if you attend 100 classes.