If a ≤ 0 and b ≥ 0, then y = -ax - b has nonnegative slope and a nonpositive y-intercept.
So, all points in the second quadrant are points in the solution set of y ≥ -ax - b. The solution set contains other points as well.
Examples: a = -3 and b = 2 So, y ≥ 3x - 2
a = 0 and b = 1 So, y ≥ -1
a = -5 and b = 0 So, y ≥ 5x