Question

tính 1+2+4+8+16+32+...+1024

giúp mk nha

Answer 1

Đặt A = 1 + 2 + 4 + 8 + ..... + 1024

=> 2A = 2 + 4 + 8 + ..... + 2048

=> 2A - A = 2048 - 1

=> A = 2047

Answer 2

Đặt A = 1 + 2 + 4 + 8 + ... + 1024

=> 2A = 2 + 4 + 8 + ... + 2048

=> 2A - A = 2048 - 1

=> 2A = 2047

Answer 3

Đặt A =1+2+4+8+16+32+.....+1024

2A=2x(1+2+4+8+16+32+............+1024)

2A=2+4+8+......+2048

2A-A=(2+4+8+............+2048)-(1+2+4+............+1024)

A=2048 - 1

A=2047

Answer 4

Đặt T=1+2+4+8+16+32+.....+1024

=>2T=2+4+8+.....+2048

=>2T-T=(2+4+8+.....+2048)-(1+2+4+....+1024)

=>T=2048-1

=>t=2047

Vậy T=2047