Vocabulary

Slope – describes the steepness of a line. It is the ratio of the rise divided by the run.

Rise – It is the vertical change between two points. It is calculated by subtracting the y-coordinates of the points. Going up from the left point to the right point indicates a positive rise. Going down from the left point to the right point indicates a negative rise.

Run – It is the horizontal change between two points. It is calculated by subtracting the x-coordinates of the points. Going right from one point to the other indicates a positive run. Going left from one point to the other indicates a negative run.

Concept

Find the slope from given two ordered pairs. 

Rules

1. Subtract the y-coordinates of both ordered pairs to find the vertical change. This is the rise.
2. Subtract the x-coordinates of both ordered pairs to find the horizontal change. This is the run.
3. Calculate the slope by dividing the rise by the run.

slope m = yb-yaxb-xa

Example

Find the slope of the line that passes through points A (-2, 5) and B (6, 4).

Solution

To find the slope, use the formula,

m = yb-yaxb-xa 

m = 4-56-(-2) = 4-56+2 = -18

Pre-requisite Skills

Slope (8.3.2)

Constant rate of Change (8.3.1)