I'll do the first one to get you started
So we have g(f(x)) which means that we start with g(x) and replace the 'x' with 'f(x)' to get g(f(x))
g(x) = ( x - 4 )/2
g(f(x)) = ( f(x) - 4)/2 .... replace every x with f(x)
g(f(x)) = (2x+4-4)/2 .... replace f(x) on the right side with 2x+4
g(f(x)) = (2x+0)/2
g(f(x)) = (2x)/2
g(f(x)) = 1x/1
g(f(x)) = 1x
g(f(x)) = x
Let me know if you need help with the other one.
