# How do you find the slope perpendicular to x + y = -3?

Jun 15, 2015

A slope of $1$ is perpendicular to $x + y = - 3$

#### Explanation:

If we rewrite $x + y = - 3$ in slope-intercept form, we get

$\textcolor{w h i t e}{\text{XXXX}}$$y = \left(- 1\right) x - 3$ with a slope of $m = \left(- 1\right)$

For any slope $m$, the slope perpendicular to it is $\left(- \frac{1}{m}\right)$

So the slope perpendicular to $x + y = - 3$ is $\left(- \frac{1}{- 1}\right) = 1$