## Algebra 1: Common Core (15th Edition)

We follow the instructions and plug -3 in for r and 5 in for s. This leaves us with the expression: $\frac{-9}{5^{-2}}$ Recall the equation: $a^{-n}= \frac{1}{a^{n}}$. Thus, we put $5^{-2}$ in the numerator of the fraction with a positive exponent. Thus, we find that the expression becomes: $-9\times5^{2}=-225$