1加1/2减5/6加7/12减9/20加11/30减13/42计算

问题描述:

1加1/2减5/6加7/12减9/20加11/30减13/42计算

原式=1+1/2-(1/2+1/3)+(1/3+1/4)-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)
=1-1/7
=6/7