answer: y = -3x + 1
step-by-step process
find the slope first using (y-y)/(x-x)
(4-(-5))/(-1-2) = 9/(-3)
m = -3
then use one of the points to find the y-intercept by putting it in y=mx+b, substituting m with -3 (aka the slope) as well
4 = -3(-1) + b
4 = 3 + b
4 - 3 = 3 + b - 3
1 = b
therefore, the equation for the line is: y=-3x+1
