Question

cho A = 2^100 - 2^99 - 2^98 - 2^97 - ... - 2^2 - 2

Answer 1

A=2^201-2/3

Answer 2

A = 2^100 - 2^99 - 2^98 - 2^97 - ... - 2^2 - 2

A = 2^100-(2^99+2^98+2^97+...+2^2+2)

=> A = 2^100-B            (Ta đặt tổng: 2^99+2^98+2^97+...+2^2+2 là B)

B=2^99+2^98+2^97+...+2^2+2

=> 2B=2^100+2^99+2^98+...+2^3+2^2

=> 2B-B=(2^100+2^99+2^98+...+2^3+2^2)-(2^99+2^98+2^97+...+2^2+2)

=>   B   =           2^100-2

=> A-B=2^100-(2^100-2)

=> A-B=2^100-2^100+2

=> A-B=        2.

Vậy A=2

K mình nhá, mình giải chi tiết rồi đó nha !!!