Find the Equation with a Point and Slope What is the equation of the line that passes through the point (-6,-5) and has a slope of -1/2 ?

What is the equation of the line that passes through the point $(- 6, - 5)$ and has a slope of $- \frac{1}{2}$ ?

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.

$y = (- \frac{1}{2}) \cdot x + b$

Substitute the value of $x$ into the equation.

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

Substitute the value of $y$ into the equation.

$- 5 = (- \frac{1}{2}) \cdot (- 6) + b$

Find the value of $b$ .

Rewrite the equation as $- \frac{1}{2} \cdot - 6 + b = - 5$ .

$- \frac{1}{2} \cdot - 6 + b = - 5$

Simplify each term.

Cancel the common factor of $2$ .

Move the leading negative in $- \frac{1}{2}$ into the numerator.

$\frac{- 1}{2} \cdot - 6 + b = - 5$

Factor $2$ out of $- 6$ .

$\frac{- 1}{2} \cdot (2 (- 3)) + b = - 5$

Cancel the common factor.

$\frac{- 1}{2} \cdot (2 \cdot - 3) + b = - 5$

Rewrite the expression.

$- 1 \cdot - 3 + b = - 5$

Multiply $- 1$ by $- 3$ .

$3 + b = - 5$

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

Subtract $3$ from both sides of the equation.

$b = - 5 - 3$

Subtract $3$ from $- 5$ .

$b = - 8$

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.

$y = - \frac{1}{2} x - 8$

Step 3