|1/3-1/2|+|1/4-1/3|+|1/5+1/4|+...+|1/100-1/99|=?有谁能解急

|1/3-1/2|+|1/4-1/3|+|1/5+1/4|+...+|1/100-1/99|=?有谁能解急 1/1×2+1/2×3+1/3×4+1/4×5+.+1/98×99+1/99×100=? 1/1*2+1/2*3+1/3*4+1/4*5+.1/98*99+1/99*100=? 1*2/1+2*3/1+3*4/1+.98*99/1+99*100/1=? (1+1/1*3)*(1+1/2*4)*(1+1/3*5).(1+1/98*100)*(1+1/99*101) (1+1/1+3)*(1+1/2*4)*(1+1/3*5)*.*(1+1/98*100)*(1+1/99*101) （1）：1/1*2+1/2*3+1/3*4+1/4*5+.1/99*100=? 1/1*2*3*4+1/2*3*4*5+...+1/97*98*99*100=? (1-1/2)(1-1/3)(1-1/4).(1-1/99)(1-1/100)等于? 六年级数学题/(1*2)+1/(2*3)+1/(3*4)+1/(4*5)+1/(5*6)+.+1/(99*100)=? 1/1*2*3+1/2*3*4+1/3*4*5+...+1/99*100*101 1/1*2*3+1/2*3*4+1/3*4*5+.1/99*100*101