A = 1x2x3x4 - 2x3x4x5 + 3x4x5x6 - 4x5x6x7 +...+ 2525x2526x2527x2528?
cách tính bài : B = 1/1x2x3x4 + 1/2x3x4x5+ ... + 1/27x28x29x30
C= 1/1x2x3x4+1/2x3x4x5+....+1/97x98x99x100
C=1x2+2x3+3x4+........+99x100
D=1x2x3+2x3x4+3x4x5+.......+98x99x100
E=12+22+52+.......+992
F=1/1x2+1/2x3+..........+1/99x100
G=1/1x2x3+1/2x3x4+........+1/99x98x100
H= 1/1x2x3x4+1/3x4x5x6+............+1/97x98x99x100
K= 1+1/2(1+2)+1/3(1+2+3)+........+1/30(1+2+30)
L=1/21+1/22+1/23+1/24+..............+1/210
M=2015/2015x2017-20162
\(\frac{ }{ }\)
1x2+1x2x3+1x2x3x4+1x2x3x4x5+....+1x2x3...99x100
1x2x3x4x....x9 - 1x2x3x4x...x.8 - 1x2x3x4....x8^2
CT: 1/1x2+ 1/1x2x3+ 1/1x2x3x4+ ..................+ 1/1x2x3x4x5.........100
1x2x3x4:5:6:7:8x9....x1998x1999x2000
Please!Help me :'3
Tích 1x2x3x4...x99x100 tận cùng bằng bao nhiêu chữ số 0?