First, we find the slope for the equation y = mx + b, where m is slope and b is the y-intercept.
(1 - (-5)) / (4 - (-4))
(1 + 5) / (4 + 4)
6 / 8
3 / 4
That means our slope, or m, is 3/4.
So, our current equation is y = 3/4 x + b
Then, we plug in a point - say, (4 , 1).
1 = 3/4 * 4 + b
1 = 3 + b
-2 = b
That means our equation is y = 3/4 x - 2