What is the equation of the line passing through #(-2,2)# and #(-1,-2)#?

1 Answer
Nov 17, 2015

Your answer must be in the form of y=mx+b

Explanation:

To find the equation of this line, first write out slope-intercept form:
y=mx+b
m is the slope, and b is the y intercept. In your final equation, you will leave x and y as x and y.

The first thing to do is find the slope. We know the equation for this is (Change in y)/(Change in x). Therefore the slope would equal
(-2-2)/(-1-(-2)).
I assume you understand how to calculate slope. Simplified, that gives us
-4/1
or -4
Now that we know the slope, our equation looks like this (since slope is m)
y=-4x+b
All we have to do now is find b, or the y intercept. To do this, we simply take one of the coordinates (we'll use the first one) and plug in -2 for x and 2 for y (the x and y points).
Your equation will look like:
(2)=-4(-2)+b
Solve for b. You should get b equal to -6.
Put that in for b and your final equation looks like this:
y=-4x-6