Question

qual é a reposta do cálculo da soma dos onze primeiros termos da P.G.
(2,4,8, ....)

Answer 1

$P.G=(2,4,8...) \\ a_{1} =2 \\ n=11 \\ q=2;pois \frac{8}{4} =2,ou, \frac{4}{2} =2 \\ \\ Sn= a_{1} * \frac{1- q^{n} }{1-q}$



$S_{n} =2* \frac{1- 2^{11} }{1-2} \\ \\ S_{n} =2* \frac{1-2048}{1-2} \\ \\ S_{n} =2* \frac{-2047}{-1} \\ \\ S_{n} =2*2047 \\ \\ S_{n} =4094$