Lines and the Coordinate Plane: Slope of a Line

Example

What is the slope of the line graphed below?

graph of line y equals negative 3 x plus 2 with points (1, negative 1) and (negative 1, 5)

The rise is the change in y.  Note: Even though the line is falling from left to right, indicating that the slope is negative, we still refer to it as rise. 

The rise from 5 to -1 is -6.

The run from -1 to 1 is 2.

m equals rise over run, m equals negative 6 over 2, m equals negative 3

When counting the units between points, remember that if you move down or to the left, the value is negative.