F(a)=a^4+17a^3+50a^2-39a-220 at x=-13

I assume that you meant "at a=-13", since the expression does not depend on x.

However, evaluating a function at a specific input values simply means to substitute every occurrence of the variabile with the specific value: if

then

And it becomes a simple, numerical calculation that you can do with every calculator:

46 dollars is the answer.

step-by-step explanation:

6*6 = 36,         36+10=46

lockers 1, 4, 9, 16, 25, 40, and 49 are open

i ran through it by the other answer is wrong