If you have double functions, solve the one in the parentheses first.
in f(g(2)), solve g(2) first.
So, substitute 2 in the function.
g(x) = x^2 - 6x - 7
g(2) = 2^2 - 6(2) - 7 = -15
If you substitute -15 in f(g(2)), it becomes f(-15).
f(x) = x + 8
f(-15) = -15 + 8
f(-15) = -7
The answer for f(g(2)) is -7.