Answer
$t=2$
Work Step by Step
$(\frac{1}{3})^{t}=\frac{1}{9}$
$(\frac{1}{3})^{t}=\frac{1^{2}}{3^{2}}$
$(\frac{1}{3})^{t}=(\frac{1}{3})^{2}$
$t=2$
Check:
$(\frac{1}{3})^{2}\overset{?}{=}\frac{1}{9}$
$\frac{1^{2}}{3^{2}}\overset{?}{=}\frac{1}{9}$
$\frac{1}{9}=\frac{1}{9}$.