Question

[Đức Mạnh]

1+2+2²+2³+...+2⁶³=2⁶⁴-1

Answer 1

[Đức Mạnh]

tính như nào nhỉ

Answer 2

[Yeutoanhoc]

`1+2+2^2+2^3+....+2^63`

`=2+2+2^2+2^3+....+2^63-1`

`=2.2+2^2+2^3+....+2^63-1`

`=2^2+2^2+2^3+....+2^63-1`

`=2.2^2+2^3+....+2^63-1`

`=2^3+2^3+...2^63-1`

`=2.2^3+....+2^63-1`

`=2^4+....+2^63-1`

`=2^{63}.2-1=2^64-1`