Question 741080
Ok....  read the numbers in the parenthesis from the list of x values and follow down to the appropriate letter.  Either f or g

a) f(4) is 1; and f(1)= 4; so f(f(4)) = 4
b) g(1) = 1 and f(1) = 4; so f(g(1)) = 4
c) for what x is g(f(x)) = 4....here, you have to work backwards.

Start with where g(x) = 4 and notice it is when x = 3
So, go to where f(x) = 3 and notice it is when x = 0

So, when x = 0, g(fx)) = 4 
Proof:

f(0) = 3; g(3) = 4.