Tính 1/1x2x3+ 1/ 2x3x4 + 1/3x4x5 + 1/ 5x6x7 + ...............+ 1/ 35x36x37
TÍNH TỔNG:1x2x3+2x3x4+3x4x5 + ...+ n.(n+1)(n+2)
Tính:
1/1x2x3 + 1/2x3x4 + 1/3x4x5 + ...........+ 1/ 98 x 99 x 100
Giúp mình với. Cảm ơn nhiều!
Tính:
1/(1x2x3) + 1/(2x3x4) + 1/(3x4x5) + ... + 1/(100x101x102) = ?
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
1x2x3+2x3x4+3x4x5+...+(n-1)xnx(n+1)
1x2x3+2x3x4+3x4x5+...+98x99x100