1/2+1/6+1/12+1/20+1/30=
问题描述:
1/2+1/6+1/12+1/20+1/30=
要算式
答
1/2+1/6+1/12+1/20+1/30
=1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6
=1/2+1/2-1/6
=5/6