Answer
$-5^{-2}=-\dfrac{1}{(5)^2}=-\dfrac{1}{25}$
Work Step by Step
RECALL:
The negative-exponent rule of exponents states that:
$a^{-m} =\dfrac{1}{a^m}$ and $\dfrac{1}{a^{-m}} = a^m$, where $a \ne 0$.
Use the negative-exponent rule to find:
$-5^{-2} =-(5^{-2})=-\dfrac{1}{(5)^2}=-\dfrac{1}{25}$
