What is the equation of the line between (-7,2) and (7,-38)?

1 Answer
Jun 25, 2018

Slope-intercept form: y=-20/7 x-18
Standard form: 20x+7y=-126

Explanation:

I will assume that you want the equation in slope-intercept form. Here, we can use the format for finding the slope given two points, which is

(y_2-y_1)/(x_2-x_1)

In our problem (x_1,y_1) is (-7,2) and (x_2,y_2) (7,-38). We can insert values and find the slope:

(-38-2)/(7-(-7))=-40/(7+7)=-40/14=-20/7

Next, we choose one of our coordinates and put that into the formula for a line in slope-intercept form,

y=mx+b

Let's choose (-7,2):

2=-20/7(-7)+b
2=20+b
-18=b

This gives us our final equation, y=-20/7 x-18.

If you needed standard form, here's how we can do that:

20/7 x+y=-18
7*(20/7 x+y)=(-18)*7
20x+7y=-126

Hope this helps!