# How do you find the slope of a line that is perpendicular to the line #y= x/-5 - 7#?

##### 1 Answer

is the equation of a line with slope

If a line has slope

So a line perpendicular to your line of slope

One way I like to picture this is as follows:

Suppose a line is given in slope-intercept form as

where

If we reflect that line in the line

If we reflect this new line in the

The total geometric effect of these two reflections is a rotation around the origin by a right angle, that is our new line is perpendicular to the old line.

Next let's rearrange into slope, intercept format. First subtract

Then divide both sides by