Answer
$$\frac{1}{p^{10}}$$
Work Step by Step
An expression raised to a negative power is equal to the reciprocal of that expression raised to the same positive power:
$$(p^{5})^{-2}= \frac{1}{(p^{5})^{2}}.$$
Multiply the exponents to raise a power to a power:
$$\frac{1}{p^{5\times 2}}=\frac{1}{p^{10}}.$$