Remember that
The average rate of change is given by the formula
[tex]\frac{f(b)-f(a)}{b-a}[/tex]
In this problem we have
b=5
a=1
f(a)=f(1)=(1)^2-4(1)+1=-2
f(b)=f(5)=(5)^2-4(5)+1=6
substitute given values in the formula
[tex]\frac{6-(-2)}{5-1}=\frac{8}{4}=2[/tex]
The answer is 2
