Answer:
34
Step-by-step explanation:
The average rate of change of f(x) in the closed interval [ a, b ] is
[tex]\frac{f(b)-f(a)}{b-a}[/tex]
Here [ a, b ] = [ 1, 6 ], thus
f(b) = f(6) = 6³ - 9(6) = 216 - 54 = 162
f(a) = f(1) = 1³ - 9(1) = 1 - 9 = - 8
average rate of change = [tex]\frac{162-(-8)}{6-1}[/tex] = [tex]\frac{170}{5}[/tex] = 34
