Answer
$9$
Work Step by Step
We rewrite the given expression as a division problem: $s^0\div r^{-2}$
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:
$s^0\div\frac{1}{r^2}$
To divide by a fraction, we multiply by the reciprocal: $s^0\times r^2$
The zero as an exponent rule states that for every nonzero number $a$, $a^0=1$. Since $s^0 = 1$ and the product of $1$ and any number is the original number, we get rid of the $s^0$ term.
$r^2$
We plug in the value for $r$: $(-3)^2$
We simplify: $9$
