数学计算题脱式简算

4个回答

  • 1+(1+1/2)+(1+1/2+1/3)+……+(1+1/2+1/3+1/4+……+1/2011)

    =(1+1+1+……+1)+(1/2+1/2+1/2+……+1/2)+(1/3+1/3+……+1/3)+……+(1/210+1/210)+1/2011

    =2001×1+2000×(1/2)+1999×(1/3)+……+2×(1/2010)+1×(1/2011)

    ∴原式=2012×(1+1/2+1/3+…+1/2011)-[1+(1+1/2)+(1+1/2+1/3)+…+(1+1/2+1/3+…+1/2011)]

    =(2012-2011)×1+(2012-2010)×(1/2)+(2012-2009)×(1/3)+……+(2012-2)×(1/2010)

    +(2012-1)×(1/2011)

    =1+1+1+……+1

    =2011