Find the Equation Using Slope-Intercept Form m=-3 , (3,5)

$m = - 3$ , $(3, 5)$

Step 1

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.

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

Substitute the value of $y$ into the equation.

$5 = (- 3) \cdot (3) + b$

Find the value of $b$ .

Rewrite the equation as $(- 3) \cdot (3) + b = 5$ .

$(- 3) \cdot (3) + b = 5$

Multiply $- 3$ by $3$ .

$- 9 + b = 5$

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

Add $9$ to both sides of the equation.

$b = 5 + 9$

Add $5$ and $9$ .

$b = 14$

Step 2

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.

$y = - 3 x + 14$

Step 3