Answer
$ f^{-1}(x)=x-8$
Work Step by Step
We are given the function, $f(x)=x+8$. First, we must replace $f(x)$ with y.
$y=x+8$
Next, interchange x and y.
$x=y+8$
Next, solve for y by subtracting 8 from both sides.
$y=x-8$
Finally, replace y with $f^{-1}(x)$.
$ f^{-1}(x)=x-8$
