well, looking at the table there, we can see that when x = 0, h(x) = 7, and when x = 1, h(x) = 9, so let's start
[tex]h(x)=a\cdot b^x \\\\[-0.35em] ~\dotfill\\\\ \begin{cases} x=0\\ h(x)=7 \end{cases}\implies 7=a\cdot b^0\implies 7=a\cdot 1\implies 7=a~\hfill \underline{h(x)=7b^x} \\\\[-0.35em] ~\dotfill\\\\ \begin{cases} x=1\\ h(x)=9 \end{cases}\implies 9=7b^1\implies 9=7b\implies \cfrac{9}{7}=b~\hfill \underline{h(x)=7\left( \frac{9}{7} \right)^x}[/tex]