Apply the general formula to solve
[tex]ar = 9 \\ a {r}^{3} = 81 \\ \frac{{ar}^{3} }{ar} = \frac{81}{9} \\ {r}^{2} = 9 \\ r = 3 \: \\ therefore \: a = 3[/tex]
Then, use the sum formula
[tex] \frac{a( {r}^{n} - 1) }{r - n} \\ \frac{3( {3}^{5} - 1)}{3 - 1} = 363[/tex]
Hope this helps!
