Chapter 7 - Exponents and Exponential Functions - 7-1 Zero and Negative Exponents - Practice and Problem-Solving Exercises - Page 417: 9

$\frac{1}{9}$

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: $\frac{1}{3\times3}=\frac{1}{9}$