Using the two points given: (-1,-1) and (2,-2) you can create a linear equation in the form y=mx+b where m is the slope and b is the y intercept.
Creating a system of equations plugging in the two known points:
-1=m(-1)+b
-2=m(2)+b
Solving the first equation for b, you get b=-1+m, plugging this value in for b in the second equation, you get:
-2=m(2)+(-1+m)
-2=2m-1+m
-2=3m-1
-1=3m
m=\(\frac{-1}{3}\)
b=-1+m
b=-1+\(\frac{-1}{3}\)
b=-4/3=-1.33
y=mx+b
y=\(\frac{-1}{3}x- \frac{4}{3}\)
m is the slope, b is the y intercept
