\(E=1+2+2^2+…….+2^{2017}\)
\(\Rightarrow2E=2\left(1+2+2^2+2^3+...+2^{2017}\right)\)
\(\Rightarrow2E=2+2^2+2^3+...+2^{2018}\)
\(\Rightarrow2E-E=2+2^2+2^3+...+2^{2018}-1-2-2^2-...-2^{2017}\)
\(\Rightarrow E=2^{2018}-1\)
Vậy \(E=2^{2018}-1\)
\(E=1+2+...+2^{2017}\)
\(\Rightarrow2E=2+2^2+...+2^{2018}\)
\(\Rightarrow2E-E=\left(2+2^2+...+2^{2018}\right)-\left(1+2+...+2^{2017}\right)\)
\(\Rightarrow E=2^{2018}-1\)
\(E=1+2+2^2+............+2^{2017}\)
\(\Leftrightarrow2E=2+2^2+..........+2^{2017}+2^{2018}\)
\(\Leftrightarrow2E-E=\left(2+2^2+........+2^{2018}\right)-\left(1+2+.....+2^{2017}\right)\)
\(\Leftrightarrow E=2^{2018}-1\)
E = 1 + 2 + 22 + ... + 22017
=> 2E = 2 + 22 + ... + 22017 + 22018
=> 2E - E = 22018 - 2
=> E = 22018 - 2
@Yuuki Tenpouin
Các bạn lm sai hết nhé. Người ta bảo tìm E mà các bạn tính E