Evaluate (3x)^-2

${(3 x)}^{- 2}$

Rewrite the expression using the negative exponent rule $b^{- n} = \frac{1}{b^{n}}$ .

$\frac{1}{{(3 x)}^{2}}$

Simplify the denominator.

Apply the product rule to $3 x$ .

$\frac{1}{3^{2} x^{2}}$

Raise $3$ to the power of $2$ .

$\frac{1}{9 x^{2}}$