Đặt A = 1+2+4+8+16+ ... + 1024
2A2+4+8 + 16 +32 + + 2048
2A-A (2 + 4 + 8 + 16 + 32 + ... + 2048) - (1 + 2 + 4 + 8 + 16+..+ 1024)
A = 2048 - 1
A = 2047
1/2+1/4+1/8+1/32+...+1/1024
Tính 1/2-1/4-1/8-1/16-....-1/1024
1+1/2+1/4+1/8+1/16+1/32+......+1/1024
A=1/2+1/4+1/8+1/16+.........+1/512+1/1024 = ?
A=1/2+1/4+1/8+....+1/512+1/1024
C=3/2+3/4+3/8+3/16+...+3/128
D=1/2+1/4+1/8+...+1/1024
E=5/2+5/8+5/32+5/128+5/512+5/2048
tính nhanh 1+2+4+8+16+32+...+1024+2048
Tính tổng:1 + 1/2 + 1/4 + 1/8 + 1/16 + ...+ 1/512 + 1/1024
Tính hợp lý
C= 1+2+4+8+16+.......+1024
D=1+2-3-4+5+6-7-8+9+....................+197+198-199-200+201
