To find \( C(7) \), we can use the given cost function:
\[ C(t) = 100 + 50(t - 3) \]
Substituting \( t = 7 \) into the function:
\[ C(7) = 100 + 50(7 - 3) \] \[ = 100 + 50 \times 4 \] \[ = 100 + 200 \] \[ = 300 \]
So, \( C(7) = 300 \), meaning that the cost for renting a piece of equipment for 7 hours is $300.
Now let's interpret \( C(5) = 200 \) in the context of this problem:
Using the function again, substitute \( t = 5 \):
\[ C(5) = 100 + 50(5 - 3) \] \[ = 100 + 50 \times 2 \] \[ = 100 + 100 \] \[ = 200 \]
Thus, \( C(5) = 200 \) means that the cost for renting a piece of equipment for 5 hours is $200.