## Algebra 1

$\frac{7st^3}{5}$
We rewrite the given expression as a division problem: $7s\div5t^{-3}$. 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 second term: $7s\div\frac{5}{t^3}$. To divide by a fraction, we multiply by the reciprocal: $7s\times\frac{t^3}{5}=\frac{7st^3}{5}$