Find f(g(x)) f(x)=x+7 and g(x)=x-7

$f (x) = x + 7$ and $g (x) = x - 7$

Set up the composite result function.

$f (g (x))$

Evaluate $f (x - 7)$ by substituting in the value of $g$ into $f$ .

$f (x - 7) = (x - 7) + 7$

Combine the opposite terms in $(x - 7) + 7$ .

Add $- 7$ and $7$ .

$f (x - 7) = x + 0$

Add $x$ and $0$ .

$f (x - 7) = x$