Find the Slope of a Parallel Line 4x+5y=12

$4 x + 5 y = 12$

Rewrite in slope-intercept form.

The slope-intercept form is $y = m x + b$ , where $m$ is the slope and $b$ is the y-intercept.

$y = m x + b$

Subtract $4 x$ from both sides of the equation.

$5 y = 12 - 4 x$

Divide each term in $5 y = 12 - 4 x$ by $5$ and simplify.

Divide each term in $5 y = 12 - 4 x$ by $5$ .

$\frac{5 y}{5} = \frac{12}{5} + \frac{- 4 x}{5}$

Simplify the left side.

Cancel the common factor of $5$ .

Cancel the common factor.

$\frac{5 y}{5} = \frac{12}{5} + \frac{- 4 x}{5}$

Divide $y$ by $1$ .

$y = \frac{12}{5} + \frac{- 4 x}{5}$

Simplify the right side.

Move the negative in front of the fraction.

$y = \frac{12}{5} - \frac{4 x}{5}$

Write in $y = m x + b$ form.

Reorder $\frac{12}{5}$ and $- \frac{4 x}{5}$ .

$y = - \frac{4 x}{5} + \frac{12}{5}$

Reorder terms.

$y = - (\frac{4}{5} x) + \frac{12}{5}$

Remove parentheses.

$y = - \frac{4}{5} x + \frac{12}{5}$

Using the slope-intercept form, the slope is $- \frac{4}{5}$ .

$m = - \frac{4}{5}$

All lines that are parallel to $y = - \frac{4}{5} x + \frac{12}{5}$ have the same slope of $- \frac{4}{5}$ .

$m_{parallel} = - \frac{4}{5}$