Question

1+2+2^2+2^3+...+2^2015
( ^ este la putere)

Va rog! Dau coroana!

Answer 1

$S = 2^0+2^1+2^2+2^3+...+2^{2015}\\ 2S = \,\,\,\,\,\,\,\,\,\,2^1+2^2+2^3+...+2^{2015}+2^{2016} \\ --------------------\\\\2S-S=2^{2016}-2^0\\ \\ S = 2^{2016}-1$