#### Answer

m=$\frac{y_2-y_1}{x_2-x_1}$

#### Work Step by Step

Slope is defined as the "rise" of a line over the "run" of a line. This is expressed as the difference of two y-values divided by the difference between their corresponding x-values. The mathematical expression for this is $\frac{y_2-y_1}{x_2-x_1}$.