## Algebra and Trigonometry 10th Edition

$\frac{1}{81}=9^{-2}$
$\log_{9}\frac{1}{81}=-2$ $y=log_{a}x$ if and only if $x=a^{y}$ Hence, $\log_{9}\frac{1}{81}=-2$ implies $\frac{1}{81}=9^{-2}$