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:

logv3(x+2)=1

rewrite in exponential form:

logb(x) = y is equal to b^y =x

b = 3, y = 1

now solve for x:

3^1 = x+2)

x = 3-2

x = 1

see the picture for the graph.