S=3^2034114 mở sách lớp 6 ra mà xem nha !!! ^_^
\(S=3^0+3^1+3^2+....+3^{2016}+3^{2017}\)
\(3S=3\left(3^0+3^1+3^2+...+3^{2016}+3^{2017}\right)\)
\(3S=3+3^2+3^3+...+3^{2017}+3^{2018}\)
\(3S-S=3^{2018}-3^0\)
\(=>2S=3^{2018}-3^0\)
\(=>S=\frac{3^{2018}-3^0}{2}\)