Evaluate -8^(-2/3)

$- 8^{- \frac{2}{3}}$

Step 1

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

$- \frac{1}{8^{\frac{2}{3}}}$

Step 2

Simplify the denominator.

Rewrite $8$ as $2^{3}$ .

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

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

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

Cancel the common factor of $3$ .

Cancel the common factor.

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

Rewrite the expression.

$- \frac{1}{2^{2}}$

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

$- \frac{1}{4}$

Step 3

The result can be shown in multiple forms.

Exact Form:

$- \frac{1}{4}$

Decimal Form:

$- 0.25$