(1/1*4)+(1/4*7)+(1/4*10)+.+(1/2008*2011)=(1/3)×(1-1/4)+(1/3)×(1/4-1/7)+...+(1/3)×(1/2008-1/2011)=(1/3)×(1-1/4+1/4-1/7+...+1/2008-1/2011)=(1/3)×(1-1/2011)=(1/3)×(2010/2011)=670/2011;很高兴为您解...