Part A
g(9) = 6
g(49) = 14
The rate of change g(x) over the interval [9,49] is:
[tex]\frac{g(49)-g(9)}{49-9}=\frac{14-6}{40}=\frac{8}{40}=\frac{1}{5}[/tex]
Likewise:
g(25)=10
g(81)=18
The rate of change of g(x) over the interval [25,81] is:
[tex]\frac{g(81)-g(25)_{}}{81-25}=\frac{18-10}{56}=\frac{8}{56}=\frac{1}{7}[/tex]
The difference will be:
[tex]\begin{gathered} =\frac{1}{5}-\frac{1}{7} \\ =0.06\text{ (to the nearest hundredth)} \end{gathered}[/tex]
Part B
g(121)=11 x 2=22
g(225)= 15 x 2 =30
Therefore, the rate of change over the interval [121,225]
[tex]=\frac{g(225)-g(121)}{225-121}=\frac{30-22}{104}=\frac{8}{104}=\frac{1}{13}[/tex]