2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1+110/1=几分之几

来源：学生作业帮助网编辑：作业帮时间：2024/11/05 23:32:47

2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1+110/1=几分之几
2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1+110/1=几分之几

2/1+6/1+12/1+20/1+30/1+42/1+56/1+72/1+90/1+110/1=几分之几
规律如下：
2=1x2
6=2x3
12=3x4
20=4x5
30=5x6
.
=1/nx(n+1）n=1...i(i=11)求和

440/1

1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90 ＝1/（1*2）+1/（2*3）+1/（3*4）+1/（4*5）+1/（5*6）+1/（6*7）+1/

2%1+6%1+12%1+20%1+30%1 1/2+1/6+1/12+1/20+1/30 1/2,-1/6,1/12,-1/20,1/30 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72 1+1/2+1/12+1/6+1/20+1/30+1/40+1/56 1+1/2+1/6+1/12+1/20+1/30.+1/901+1/2+1/6+1/12+1/20+1/30+.+1/90简便计算 1/2+1/6+1/12+1/20+1/30+1/42+1/56 简算 1/2+1/6+1/12+1/20+1/30+1/42+1/56简算, 简便运算：1/2+1/6+1/12+1/20+1/30+1/42+1/56 1+1/2+1/6+1/12+1/20+1/30+1/42的简便计算 2/1+6/1+12/1+20/1+30/1+42/1+56/1=? 1/2 - 1/6 - 1/12 - 1/20 - 1/30 - 1/42 - 1/56怎么算 1/2+1/6+1/12+1/20+1/30+.1/380+1/420= 1+1/2+1/6+1/12+1/20+1/30+1/42=? 1/2+1/6+1/12+1/20+1/30+1/42+1/56 1/2-1/6-1/12-1/20-1/30-1/42-1/56等于多少 2/1+6/1+12/1+20/1+30/1+42/1+56/1=