SOLUTION
The formula for average rate of change is given as
[tex]A=\frac{f(b)-f(a)}{b-a}[/tex]
The given interval is x=7 to x=9
Hence the average rate of change becomes
[tex]A=\frac{f(9)-f(7)}{9-7}[/tex]
From the graph,
When x =7, f(7)=-7
When x=9, f(9)= -1
The average rate of change is
[tex]A=\frac{-1-(-7)}{9-7}[/tex]
Solve for A
[tex]\begin{gathered} A=\frac{-1+7}{2} \\ A=\frac{6}{2} \\ A=3 \end{gathered}[/tex]
Therefore the average rate of change is 3
