1-1/6-1/12-1/20-1/30-1/42-1/56-1/72-1/90=1-(1/6+1/12+1/20+1/30+1/42+1/56+1/72+1/90)=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+1/9-1/10)=1-(1/2-1/10)=1-2/5=3/5祝学习进步
