First you need to find the slope.
y1 - y2/x1- x2 you can choose any order pair to be the first or second one, but make sure you remain consistent.
I chose order pair A to be 1 and order pair B to be 2
3 - (-1)/ (-1) - 2 = 4/(-3) *this is the slope aka the k value
Plug in one of the order pairs for y and x
3= -4/3(-1) + b
3 = 4/3 + b
3 - 4/3 = b
5/3 = b
Y= -4/3x + 5/3
