The average rate of change is given by
[tex]A(x)=\frac{f(b)-f(a)}{b-a}[/tex]Here a=8 and b=8+h
[tex]\begin{gathered} f(x)=5x+3 \\ f(8)=5\times8+3=43 \\ f(8+h)=5(8+h)+3 \\ \text{ =40+5h+3} \\ \text{ =43+5h} \end{gathered}[/tex]Thus,
[tex]A(x)=\frac{43+5h-43}{8+h-8}=\frac{5h}{h}=5[/tex]Thus the average rate is 5.
