## Intermediate Algebra (12th Edition)

a. B. $\frac{1}{25}$ b. D. $-\frac{1}{25}$ c. B. $\frac{1}{25}$ d. D. $-\frac{1}{25}$
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. $-(-5)^{-2}=-\frac{1}{(-5)^{2}}=-\frac{1}{-5\times-5}=-\frac{1}{25}$