# How do you find the slope that is perpendicular to the line 9x+3y=0?

Jun 25, 2017

The slope is $= \frac{1}{3}$

#### Explanation:

Let's rewrite the equation

$9 x + 3 y = 0$

$3 y = - 9 x$

$y = - 3 x$

The slope of a line with equation

$y = m x + c$

is $= m$

Here, we have $m = - 3$

The slope of the line $m '$ perpendicular to another line is

$m m ' = - 1$

$m ' = - \frac{1}{m} = \frac{- 1}{- 3} = \frac{1}{3}$