Question

Answer 1

`#040911`

`A = 1 + 2 + 4 + 8 + ... + 8192`

`A = 1 + 2 + 2^2 + 2^3 + ... + 2^13`

`2A = 2 + 2^2 + 2^3 + 2^4 + ... + 2^14`

`2A - A = (2 + 2^2 + 2^3 + ... + 2^14) - (1 + 2 + 2^2 + ... + 2^13)`

`A = 2 + 2^2 + 2^3 + ... + 2^14 - 1 - 2 - 2^2 - ... - 2^13`

`A = 2^14 - 1`

Vậy, `A = 2^14 - 1.`

Answer 2

A=1+2+2^2+...+2^13

=>2A=2+2^2+2^3+...+2^14

=>2A-A=2^14-1

=>A=2^14-1