# How do you find the slope of a line perpendicular to #3x+y=15#?

##### 1 Answer

Jun 17, 2015

Subtracting

Any line perpendicular to it will have slope

#### Explanation:

Either just use the answer above, asserting the

Starting with

Then reflect in the

These two geometric steps are equivalent to rotating by a right angle centred on the origin.

Next add

Finally divide both sides by

This is in slope-intercept format with slope