,

Use the formula for the equation of a line to find .

Substitute the value of into the equation.

Substitute the value of into the equation.

Substitute the value of into the equation.

Find the value of .

Rewrite the equation as .

Multiply by .

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

Add to both sides of the equation.

Add and .

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

Find the Equation Using Slope-Intercept Form m=-3 , (7,8)