# Precalculus Examples

,

Slope is equal to the change in over the change in , or rise over run.

The change in is equal to the difference in x-coordinates (also called run), and the change in is equal to the difference in y-coordinates (also called rise).

Substitute in the values of and into the equation to find the slope.

Simplify.

Simplify the numerator.

Multiply by .

Add and .

Simplify the denominator.

Multiply by .

Subtract from .

Divide by .

Substitute the value of into the slope-intercept form of the equation, .

Substitute the value of into the slope-intercept form of the equation, .

Substitute the value of into the slope-intercept form of the equation, .

Rewrite the equation as .

Simplify each term.

Multiply by .

Multiply by .

Move all terms not containing to the right side of the equation.

Subtract from both sides of the equation.

Subtract from .

The values of the slope and y-intercept are and