Answer:
13
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 ] = [2, 6 ]
f(b) = f(6) = 6² + 5(6) - 8 = 36 + 30 - 8 = 58
f(a) = f(2) = 2² + 5(2) - 8 = 4 + 10 - 8 = 6
Hence
average rate of change = [tex]\frac{58-6}{6-2}[/tex] = [tex]\frac{52}{4}[/tex] = 13
