pakai pembahasan nya ya...

[tex] {ar}^{5} = 160 \\ ar = 10 \\ - - - - - - - - - \div \\ {r}^{4} = 16 \\ r = 2 \\a = 10 \div 2 = 5 \\ s10 = 5( {2}^{10} - 1) \div (2 - 1) \\ s10 = \frac{5(1023)}{1} = 5.115[/tex]