Answer
$r^{8}$
Work Step by Step
We are given the expression $\frac{r^{4}}{r^{-4}}$.
To simplify, we can use the quotient rule, which holds that $\frac{a^{m}}{a^{n}}=a^{m-n}$ (where a is a nonzero real number, and m and n are integers).
$\frac{r^{4}}{r^{-4}}=r^{4-(-4)}=r^{8}$