The equation of a line is y = mx + b (m is the slope; b is the y-intercept)
We are given the slope of -2 so...
y = -2x + b
We must determine b. Since they give us a point, we can sub in the x and y coords (-2,0)
0 = -2(-2) + b
0 = 2 + b
[Subtract 2 from both sides]
0-2=2-2+b
-2=b
Now, go back to the original equation (before adding coordinates in) and input b.
y = -2x-2
