Question

1 + 2 + 2 mủ 2 + 2 mủ 3 +...+ 2 mủ 2021

Answer 1

Answer 2

Đặt `A = 1 + 2 + 2^2 + 2^3 + ... + 2^2021`

`2A = 2 + 2^2 + 2^3 + 2^4 + ... + 2^2022`

`2A - A = ( 2 + 2^2 + 2^3 + 2^4 + ... + 2^2022 ) - ( 1 + 2 + 2^2 + 2^3 + ... + 2^2021 )`

`A = 2^2022 - 1`

`#tf`