#### Answer

$\frac{1}{9}$

#### Work Step by Step

We want to simplify: $3^{-2}$
The negative exponent rule states that for every nonzero number $a$ and integer $n$, $a^{-n}=\frac{1}{a^n}$.
We use this to rewrite the expression as $\frac{1}{3^2}$.
Next, we must simplify the power on the denominator: $\frac{1}{3\times3}=\frac{1}{9}$