Question 3.3.5: Find the slope of the line through (-2, 1) and (5, -4)....

It makes no difference which ordered pair we call $\left(x_1, y_1\right)$ and which we call $\left(x_2, y_2\right)$.

$\text { Slope }=m=\frac{y_2~-~y_1}{x_2~-~x_1}=\frac{-4~-~1}{5~-~(-2)}=\frac{-5}{7}$

The slope is $-\frac{5}{7}$. Every vertical change of – 5 units (down 5 units) is accompanied by a horizontal change of 7 units (to the right 7 units). (See Figure 8.)