# How do you find the slope of a line perpendicular to the line 3x - y = 8?

For any line with a slope of $m$
all lines perpendicular to it have a slope of $\left(- \frac{1}{m}\right)$
$3 x - y = 8$
$\textcolor{w h i t e}{\text{XXXX}}$$y = 3 x - 8$ which is the slope intercept form, with a slope of $3$
Any line perpendicular to $3 x - y = 8$ will have a slope of $\left(- \frac{1}{3}\right)$