Question

1-5/6+7/12-9/2+11/30-13/42+15/56-17/72+19/90 怎么简便

Answer 1

1-(1/3+1/2)+(1/3+1/4)-(1/4+1/5)+(1/5+1/6)-(1/6+1/7)+(1/7+1/8)-(1/8+1/9)+(1/9+1/10)=1+1/2+1/10=1.6