Answer
The lines are perpendicular.
Work Step by Step
We are given the equations:
$y=3x-5$ and $y=-\frac{1}{3}x-5$
We compare the equations with the slope-intercept form of a line $y=mx+c$ and use this to find the slopes $m_1$and $m_2$ as follows
$$
m_1=3, \quad m_2=-\frac{1}{3}
.$$
Now, since $$ m_1m_2=3\cdot \frac{-1}{3}=-1$$
then the lines are perpendicular.
