(1/(1x2)/(2x3)/(3x4)):(1/(2x3)/(3x4)/(4x5)):...(1/(97*98)/(98*99)/(99*100))
(1/(1x2)/(2x3)/(3x4)):(1/(2x3)/(3x4)/(4x5)):...(1/(97*98)/(98*99)/(99*100
1/(1x2)/(2x3)/(3x4)):(1/(2x3)/(3x4)/(4x5)):...(1/(97*98)/(98*99)/(99*100
(1/(1x2)/(2x3)/(3x4)):(1/(2x3)/(3x4)/(4x5)):...(1/(97*98)/(98*99)/(99*100
1/(1x2)/(2x3)/(3x4)):(1/(2x3)/(3x4)/(4x5)):...(1/(97*98)/(98*99)/(99*100
Tính: 1+1/1x2+1/2x3+1/3x4+1/4x5+........+1/99x100+1/100x101
2021/1x2+2021/2x3+2021/3x4+2021/4x5+...+2021/9x10
tính nhanh (1x2)^-1+(2x3)^-1+(3x4)^-1+...+(2014x2015)^-1
1x2+2x3+3x4+...+x(x+1)
giúp mih với