Question

tinh :

1+2+4+8+..............................+8192

Answer 1

đặt A=tổng

=>2A=2+4+8+16+...+16384

=>2A-A=2+4+8+16+...+16384-1-2-4-8-...-8192

=>A=16384-1

A=16383

Answer 2

Đặt A = \(1+2+4+.....+8192=1+2+2^2+.....+2^{13}\)

\(2A=2+2^2+......+2^{14}\)

\(2A-A=\left(2-2\right)+\left(2^2-2^2\right)+......+2^{14}-1\)

Vậy \(A=2^{14}-1\)