Evaluate 243^(-4/5)

$243^{- \frac{4}{5}}$

Step 1

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

$\frac{1}{243^{\frac{4}{5}}}$

Step 2

Simplify the denominator.

Rewrite $243$ as $3^{5}$ .

$\frac{1}{{(3^{5})}^{\frac{4}{5}}}$

Apply the power rule and multiply exponents, ${(a^{m})}^{n} = a^{m n}$ .

$\frac{1}{3^{5 (\frac{4}{5})}}$

Cancel the common factor of $5$ .

Cancel the common factor.

$\frac{1}{3^{5 (\frac{4}{5})}}$

Rewrite the expression.

$\frac{1}{3^{4}}$

Raise $3$ to the power of $4$ .

$\frac{1}{81}$

Step 3

The result can be shown in multiple forms.

Exact Form:

$\frac{1}{81}$

Decimal Form:

$0.01234567 \dots$