Find the Equation with a Point and Slope What is the equation of the line that passes through the point (-6,-6) and has a slope of -1/3 ?

What is the equation of the line that passes through the point $(- 6, - 6)$ and has a slope of $- \frac{1}{3}$ ?

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.

$y = (- \frac{1}{3}) \cdot x + b$

Substitute the value of $x$ into the equation.

$y = (- \frac{1}{3}) \cdot (- 6) + b$

Substitute the value of $y$ into the equation.

$- 6 = (- \frac{1}{3}) \cdot (- 6) + b$

Find the value of $b$ .

Rewrite the equation as $- \frac{1}{3} \cdot - 6 + b = - 6$ .

$- \frac{1}{3} \cdot - 6 + b = - 6$

Simplify each term.

Cancel the common factor of $3$ .

Move the leading negative in $- \frac{1}{3}$ into the numerator.

$\frac{- 1}{3} \cdot - 6 + b = - 6$

Factor $3$ out of $- 6$ .

$\frac{- 1}{3} \cdot (3 (- 2)) + b = - 6$

Cancel the common factor.

$\frac{- 1}{3} \cdot (3 \cdot - 2) + b = - 6$

Rewrite the expression.

$- 1 \cdot - 2 + b = - 6$

Multiply $- 1$ by $- 2$ .

$2 + b = - 6$

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

Subtract $2$ from both sides of the equation.

$b = - 6 - 2$

Subtract $2$ from $- 6$ .

$b = - 8$

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.

$y = - \frac{1}{3} x - 8$