# Precalculus Examples

,
Find the value of the slope.
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 .
Subtract from .
Simplify the denominator.
Multiply by .
Divide by .
Find the value of the y-intercept.
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 the left side.
Multiply by .