1/2-1/3=1/6 1/3-1/4=1/12 .根据算式简算下面算式的和 1/6+1/12+1/20+1/30+1/42+1/56 等于?

问题描述:

1/2-1/3=1/6 1/3-1/4=1/12 .根据算式简算下面算式的和 1/6+1/12+1/20+1/30+1/42+1/56 等于?

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(中间的全抵消)
=1/2-1/8
=3/8