Answer
$f(g(x))=f(\frac{x}{4}+2)=4(\frac{x}{4}+2)-8=x+8-8=x$
$g(f(x))=g(4x-8)=\frac{4x-8}{4}+2=x-2+2=x$
There are no values to be excluded.
Work Step by Step
$f(g(x))=f(\frac{x}{4}+2)=4(\frac{x}{4}+2)-8=x+8-8=x$
$g(f(x))=g(4x-8)=\frac{4x-8}{4}+2=x-2+2=x$
There are no values to be excluded.