f(0) = -1/5
f(4) = 7/17
f(4) - f(0)
average rate of change = --------------
4 - 0
(7/17) - (-1/5)
average rate of change = ---------------------
4
52/85
average rate of change = ---------
4
average rate of change = 52/85 *4
average rate of change = 208/85
