The maximum speed of a truck up a steep hill is 50mph with no cargo. With 20 tons of cargo, its maximum speed is 40mph. Calculate the rate of change and explain the meaning of this rate of change in the context. (Hint: use the information above to write 2 points (x_(1),y_(1)) and (x-(2),y (2)), then calculate the rate of change) -10mph =20 tons