# What is the slope of the line perpendicular to the line whose equation is 7x-2y=9?

Oct 18, 2017

$- \frac{2}{7}$

#### Explanation:

Let's first put the line in slope-intercept form:

$7 x - 2 y = 9$

$- 2 y = - 7 x + 9$

$2 y = 7 x - 9$

$y = \frac{7}{2} x - \frac{9}{2}$

So the slope of the original line is $\frac{7}{2}$.

To find the slope of the perpendicular line, we take the negative reciprocal of the original slope.

$\frac{- 1}{\frac{7}{2}} = - \frac{2}{7}$

So the perpendicular line has a slope of $- \frac{2}{7}$