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:

wheres graph

step-by-step explanation:

1.3

step-by-step explanation:

3x2=6   9x+6

bring down the 6 on both sides

6+6=12

12= 9x

divide by 9

12/9 =

1.3 =x