Remember, David, that the slope is the difference in y's over the difference in x's, or (y2 - y1)/(y2 - y1).
How do we know which is (x2, y2) and which is (x1, y1)? It doesn't matter, as long as you go in the SAME direction.
(-5-2)/(0-4) = -7/-4 = 7/4
(2-(-5))/(4-0) = 7/4
See how they are both the same? The slope is 7/4.
Hope this helps!