The slope should be 5/2 which is found through these steps below
m = (y2 - y1)/(x2 - x1)
m = (5 - (-5))/(2 - (-2))
m = (5 + 5)/(2 + 2)
m = 10/4
m = 5/2
note how the '5's are up top and the '2's are down below. So Billy mixed up the numerator and denominator
