Answer
$$\frac{1}{x^{6}}$$
Work Step by Step
Multiply exponents to raise a power to a power. Then the expression raised to a negative power is equal to the reciprocal of that expression raised to the same positive power:
$$(x^{-2})^{3}=x^{(-2)\times 3}=x^{-6}=\frac{1}{x^{6}}.$$