## Algebra 1: Common Core (15th Edition)

$\boxed{\frac{mq^2}{n^{4}}}$
If a power on the numerator has a negative exponent, it can move to the denominator with a positive exponent, and if a power on the denominator has a negative exponent, it can move to the numerator with a positive exponent. So, $$\frac{mn^{-4}}{p^0q^{-2}} = \frac{mq^2}{p^0n^{4}}$$ Anything to the power $0$ is always $1$. Therefore, $p^0$ must be $1$. Therefore, $$\frac{mq^2}{p^0n^{4}} = \boxed{\frac{mq^2}{n^{4}}}$$