# What is the slope of the line perpendicular to  y=-5/3x -3 ?

The slope of a line perpendicular to a line with slope $m$ is $- \frac{1}{m}$. The line we are looking for, therefore, has a slope of $\frac{3}{5}$.
$y = m x + b$ where $m$ is the slope and $b$ is the y-intercept.
For another line perpendicular, the slope will be $- \frac{1}{m}$. In this case, that is $- \frac{1}{- \frac{5}{3}}$ = $\frac{3}{5}$.