1又1/3+7/12+9/20-11/30+13/42-15/56=?
问题描述:
1又1/3+7/12+9/20-11/30+13/42-15/56=?
答
1又1/3-7/12+9/20-11/30+13/42-15/56
=(1+1/3)-(1/3+1/4)+(1/4+1/5)-(1/5+1/6)+(1/6+1/7)-(1/7+1/8)
=1-1/8
=7/8