计算1/6+1/12+1/20+1/30+1/42+2/56
问题描述：
计算1/6+1/12+1/20+1/30+1/42+2/56
答
1/6+1/12+1/20+1/30+1/42+1/56
=(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+(1/5-1/6)+(1/6-1/7)+(1/7-1/8)
=1/2-1/8
=3/8
如果是
1/6+1/12+1/20+1/30+1/42+2/56
=3/8+1/56
=22/56
=11/28