Answer
$\frac{q^{4}}{p^{5}}$
Work Step by Step
We know that $a^{−n}=\frac{1}{a^{n}}$ and $\frac{1}{a^{-n}}=a^{n}$ (as long as a is a nonzero real number and n is an integer).
Therefore, $\frac{p^{-5}}{q^{-4}}=\frac{1}{p^{5}}\times q^{4}=\frac{q^{4}}{p^{5}}$.