How do you write an equation of a line that goes through (-3,-1) and (-8,-4)?

1 Answer
Noah G
Jan 25, 2016

First, find the slope. The formula for slope is m = #(y_2 - y_1)/(x_2 - x_1)#, where m represents slope

Explanation:

m = # (-4 -(-1))/(-8-(-3))#

m = #-3/-5#

m = #3/5#

Now that we know that the slope is #3/5#, we can use point slope form to find the slope intercept equation of the line. The point slope form formula is:

#y - y_1 = m(x - x_1)#

Pick one of the points to plug in for (#x_1, y_1#). I'll pick (-3,-1), but the other one would give you the same answer.

y - (-1) = #3/5#(x - (-3))

y + 1 = #3/5x# + #9/5#

y = #3/5x# + #(9 - 5)/5#

y = #3/5x# + #4/5#

The slope is #3/5# and the y intercept is #4/5#.

Related questions
See all questions in Write an Equation Given Two Points
Impact of this question
1921 views around the world
You can reuse this answer
Creative Commons License