
Luke J. answered 02/24/22
Experienced High School through College STEM Tutor
Given:
P1: (-5, 4)
P2: (3, -2)
Find:
The equation for the line that passes thru P1 & P2
Solution:
y = mx + b
Will be the equation to arrive to at the very end, but we need m & b, the slope and the y-intercept
m = ( y2 - y1 ) / ( x2 - x1 ) = ( -2 - 4 ) / ( 3 - ( -5 ) ) = -6 / 8
∴ m = - 3/4
Using either P1 or P2, plug in one of their respective x- and y-values into:
y = -3/4 x + b
I'll do (3, -2):
-2 = -3/4 ( 3 ) + b
-2 = -9/4 + b
-8 = -9 + 4b
1 = 4b
∴ b = 1/4
∴ y = -3/4 x + 1/4 is the equation of the line that passes thru both points (-5, 4) and (3, -2)
I hope this helps! Message me in the comments if you have any questions, comments, or concerns!