## Intermediate Algebra for College Students (7th Edition)

$m=\dfrac{y_2-y_1}{x_2-x_1}$
Divide both sides by $x_2-x_1$ to find: $\dfrac{y_2-y_1}{x_2-x_1}=\dfrac{m(x_2-x_1)}{x_2-x_1} \\\dfrac{y_2-y_1}{x_2-x_1}=m \\m=\dfrac{y_2-y_1}{x_2-x_1}$