Find approximate values forf'(x) at each of thex-values given in the following table. (Note: Forx= 0, 5, 10, and 15 use the interval to the right. Forx= 20 use the interval to the left.)

X = 0 5 10 15 20

f(x) = 110 80 50 43 35

f`(x) = ? ? ? ? ?

ok this is the problem that it gives me, and im not sure where to go...any help would be much appreciated