=1/2-1/3-1/4+1/3-1/4-1/5+1/5-1/6-1/7+...+1/35-1/36-1/37
giao hoán, kết hợp là ra nha
=1/2-1/3-1/4+1/3-1/4-1/5+1/5-1/6-1/7+...+1/35-1/36-1/37
giao hoán, kết hợp là ra nha
Tính nhanh:2/1x2x3+2/2x3x4+2/3x4x5+2/4x5x6+2/5x6x7+2/6x7x8
Giúp mình với!Thanks
bài 1
tính A = 1x2x3+3x4x5+5x6x7+.......+99x100x102
Tính:
1/1x2x3 + 1/2x3x4 + 1/3x4x5 + ...........+ 1/ 98 x 99 x 100
TÍNH TỔNG:1x2x3+2x3x4+3x4x5 + ...+ n.(n+1)(n+2)
1/1x2x3+1/2x3x4+1/3x4x5+....+1/48x49x50
cho tui đáp án là dc
gấp lămm
Tính :
a) 1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+.....+1
b)1/1x2x3+1/2x3x4+1/3x4x5+.....+1/98x99x100
Tính :
a) 1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+.....+1
b)1/1x2x3+1/2x3x4+1/3x4x5+.....+1/98x99x100
Tính nhanh:
1/1x2x3 + 1/2x3x4 + 1/3x4x5 + ... + 1/98x99x100
A=1x2+2x3+3x4+...+49x50
B=1x3+3x5+5x7+...+99x101
C=1x2x3+2x3x4+3x4x5+...+50x51x52
D=1x4+2x5+3x6+...+60x63
E=1x1+2x2+3x3+...+50x50
F=1x1+3x3+5x5+...+71x71
G=1x1+4x4+7x7+...+100x100
I=1x2x3+3x4x5+5x6x7+...+69x70x71