Answer
$27^{-\frac{5}{3}}$ = $\frac{1}{243}$
Work Step by Step
$27^{-\frac{5}{3}}$
= $\frac{1}{27^{\frac{5}{3}}}$
= $\frac{1}{\sqrt[3] {27^{5}}}$
As we know 27 = $3^{3}$
= $\frac{1}{3^{3\times\frac{5}{3}}}$
= $\frac{1}{3^{5}}$
= $\frac{1}{243}$
