Question

What is the equation of the line that passes through the points (-2, 1) and (1, 10)?
A 3x - y = -7
B 3x - y = -5
C 3x - y = 5
D x + 3y = -5

When I do the problem, I come up with 9... but I forget how to put it into an equation.

Answer 1

First find the slope by using the rise/run formula.
m=(1-10)/(-2-1)=(-9)/(-3)=3.
Then you have y=3x+c.
Plug in one of the points to find c.
1=3(-2)+c
7=c
y=3x+7
or
3x-y=-7