# Precalculus Examples

,

Find the value of using the formula for the equation of a line.

Substitute the value of into the equation.

Substitute the value of into the equation.

Substitute the value of into the equation.

Rewrite the equation as .

Simplify each term.

Multiply by .

Move to the left of the expression .

Multiply by .

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

Subtract from both sides of the equation.

Subtract from .

Divide each term by and simplify.

Divide each term in by .

Simplify the left side of the by cancelling the common factors.

Reduce the expression by cancelling the common factors.

Factor out of .

Move the negative one from the denominator of .

Simplify the expression.

Multiply by .

Rewrite as .

Move the negative in front of the fraction.

Now that the values of (slope) and (y-intercept) are known, substitute them into to find the equation of the line.