35分之1加35分之2加35分之3一直加到35分之34

1/20-4/77+5/60-1/78+12/35=1/20-4/77+1/12-1/78+12/35=3003/60020-780/60020+5005/60020-770/60060+1716/6

可以把20分之9拆开成1/4+1/5,21分之10拆开成1/3+1/7,24分之11拆开成1/3+1/8,35分之19拆开成2/5+1/7.再跟前面的3分之1加4分之3加5分之2加7分之5加8分之7相

3分之1加15分之1加35分之1加63分之1加99分之1=（1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11）÷2=（1-1/11）÷2=5/11

11/24+1/3+3/4+2/5+5/7+7/8+9/20+10/21+12/35=(1/3+1/8)+1/3+3/4+2/5+5/7+7/8+(1/4+1/5)+(1/3+1/7)+(1/5+1/

1/3-2/15+3/35-4/63+5/99-6/143=[1/3-2/(3×5)]+[3/(5×7)-4/(7×9)]+[5/(9×11)-6/(11×13)]=1/3×（1-2/5）+1/7×（

1/15+1/35+1/63+1/99+1/143={[(1/3)-(1/5)]/2}+{[(1/5)-(1/7)]/2}+{[(1/7)-(1/9)]/2}+{[(1/9)-(1/11)]/2}+{

您好：15分之1＋35分之1＋63分之1＋99分之1＋143分之1＋195分之1=1/3x5+1/5x7+1/7x9+1/9x11+1/11x13+1/13x15=1/2x(1/3-1/5+1/5-1

1/2X+35+1/3X+20=X(1/2+1/3)X+55=X55=X-(1/2+1/3)X=1/6XX=330

3分之1加15分之1加35分之1加63分之1加99分之1加143分之1=1/3+1/2(1/3-1/5)+1/2(1/5-1/7)+1/2(1/7-1/9)+1/2(1/9-1/11)+1/2(1/1

1/3+1/15+1/35+1/63+1/99=1/3+1/2(1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11)=1/3+1/2(1/3-1/11)=1/3+1/6-1/22=1/2

3分之1加15分之1加35分之1.加2007乘以2009分之1加2009乘以2011分之1=（1-1/3+1/3-1/5+1/5-1/7+……+1/2007-1/2009+1/2009-1/2011）

1/2+1/6++1/20+.+1/9900=1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100=1-1/100=99/100就是这样啊o(∩_∩)o

1/3+1/15+1/35+1/63=1/(1×3)+1/(3×5)+1/(5×7)+1/(7×)=1/2×[2/(1×3)+2/(3×5)+2/(5×7)+2/(7×)]=1/2×(1-1/3+1/

=-[1/(1x3)+1/(2x4)+1/(3x5)+1/(4x6)+1/(5x7)]=-1/2[1-1/3+1/2-1/4+1/3-1/5+1/4-1/6+1/5-1/7]=-1/2[1+1/2-1

1/15=1/2(1/3-1/5)1/35=1/2(1/5-1/7)1/63=1/2(1/7-1/9).所以原式=60*1/2(1/3-1/5+1/5-1/7+.+1/13-1/15)=30*(1/3

十一分之五

3分之1加15分之1加35分之1加63分之1加99分之1=1/(1x3)+1/(3x5)+1/(5x7)+1/(7x9)+1/(9x11)=1/2(1-1/3+1/3-1/5+1/5-1/7+1/7-

1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7+1/7-1/8+1/8-1/9+1/9-1/10=1-1/10=9/10这是1/2+1/6+1/12+1/20+

再问：你错了

2／3＋2／15＋2／35＋2／63=2／1×3＋2／3×5＋2／5×7＋2／7×9=2×﹙1／3＋1／3×1／5＋1／5×1／7＋1／7×1／9﹚=2×﹙2／5＋1／5×1／7＋1／7×1／9﹚=2