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

As the number of uniforms bought increases, the price increases, so we know the slope is positive. We are given two points: (5, 66) and (9, 114). In order to find the slope, we use the following equation: $\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$. Thus, we obtain: $\frac{114-66}{9-5}=\frac{48}{4}=12$