Write in Slope-Intercept Form m=-3 , (-4,12)

$m = - 3$ , $(- 4, 12)$

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

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

$y = m x + b$

Substitute the value of $m$ into the equation.

$y = (- 3) \cdot x + b$

Substitute the value of $x$ into the equation.

$y = (- 3) \cdot (- 4) + b$

Substitute the value of $y$ into the equation.

$12 = (- 3) \cdot (- 4) + b$

Find the value of $b$ .

Rewrite the equation as $(- 3) \cdot (- 4) + b = 12$ .

$(- 3) \cdot (- 4) + b = 12$

Multiply $- 3$ by $- 4$ .

$12 + b = 12$

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

Subtract $12$ from both sides of the equation.

$b = 12 - 12$

Subtract $12$ from $12$ .

$b = 0$

Now that the values of $m$ (slope) and $b$ (y-intercept) are known, substitute them into $y = m x + b$ to find the equation of the line.

$y = - 3 x$