Find the slope of the line through each pair of points.
(0, -15), (3,-6)
m =

"When a minus sign occurs with exponential notation, a certain caution is in order. For example, (-4)2 means that -4 is to be raised to the second power. Hence (-4)2 = (-4) * (-4) = 16. On the other hand, -42 represents the additive inverse of 42. Thus -42 = -16. It may help to think of -x2 as -1 * x2 ..."[1]