## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

Each tick mark represents $0.5$ units.
Slope is the rise over run (or rise divided by the run). Having a slope of $-\dfrac{2}{3}$ means that the rise is $-2$ and the run is $3$. The two points have unknown y-coordinates, but their x-coordinates are known: $(-2, y_1)$ and $(1, y_2)$ The run between the two points is $=1-(-2)=1+2=3$ (as expected) The rise is represented by $y_2-y_1$. Note that there are four tick marks from $y_1$ to $y_2$. Since the four tick marks represent two units, then each tick mark must represent $0.5$ units.