-1+6/5-12/7+20/9-11/30+13/42-15/56+17/72等于多少?
问题描述:
-1+6/5-12/7+20/9-11/30+13/42-15/56+17/72等于多少?
答
=-1+(1/2+1/3)-(1/3+1/4)+(1/4+1/5)-(1/5+1/6)+(1/6+1/7)-(1/7+1/8)+(1/8+1/9)
=-1+1/2+1/9
=11/18