Chapter 7 - Exponents and Exponential Functions - 7-3 Multipying Powers with the Same Base - Mixed Review - Page 431: 86

$\frac{4n^2}{m}$

We start with the given expression: $4m^{-1}n^2$ The negative exponent rule states that for every nonzero number $a$ and integer $n$, $a^{-n}=\frac{1}{a^n}$. We use this rule to rewrite the expression: $\frac{4n^2}{m^1}$. Since $m^1=m$, we rewrite this as $\frac{4n^2}{m}$.