分子分母不同怎么相加,不能通分,如1/2+1/6+1/12+……+1/4034072=多少

问题描述:

分子分母不同怎么相加,不能通分,如1/2+1/6+1/12+……+1/4034072=多少

原式=(1-1/2)+(1/2-1/3)+(1/3-1/4)+······+(1/2008-1/2009) =1-1/2+1/2-1/3+1/3-1/4+······+1/2008-1/2009 =1-1/2009 =2008/2009
麻烦采纳,谢谢!