# What is the slope of the line perpendicular to  y=9/4x-7 ?

Dec 16, 2015

$\left(- \frac{4}{9}\right)$

#### Explanation:

If a line has a slope of $m$
all lines perpendicular to it will have a slope of $\left(- \frac{1}{m}\right)$

$y = \frac{9}{4} x - 7$ is a line in "slope-intercept" form
with a slope of $\frac{9}{4}$

Therefore any line perpendicular to it will have a slope of
$\textcolor{w h i t e}{\text{XXX}} - \frac{1}{\left(\frac{9}{4}\right)} = - \frac{4}{9}$