1+1/3-7/12-11/30+13/42-15/56等于多少大神们帮帮忙
问题描述：
1+1/3-7/12-11/30+13/42-15/56等于多少大神们帮帮忙
答
答案是17/40 1+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 7/8 -9/20=35/40-18/40=17/40