Answer
a. B. $\frac{1}{25}$
b. D. $-\frac{1}{25}$
c. B. $\frac{1}{25}$
d. D. $-\frac{1}{25}$
Work Step by Step
According to the negative exponent rule, $a^{-n}=\frac{1}{a^{n}}$.
Therefore,
a. $5^{-2}=\frac{1}{5^{2}}=\frac{1}{5\times5}=\frac{1}{25}$
b. $-5^{-2}=-\frac{1}{5^{2}}=-\frac{1}{5\times5}=-\frac{1}{25}$
c. $(-5)^{-2}=\frac{1}{(-5)^{2}}=\frac{1}{-5\times-5}=\frac{1}{25}$
d. $-(-5)^{-2}=-\frac{1}{(-5)^{2}}=-\frac{1}{-5\times-5}=-\frac{1}{25}$