计算:1/1×6+1/6×11+1/11×16+······+1/2006×2011(写明过程理由答案)

问题描述:

计算:1/1×6+1/6×11+1/11×16+······+1/2006×2011(写明过程理由答案)

1/1×6+1/6×11+1/11×16+······+1/2006×2011
=1/5[(1-1/6)+(1/6-1/11)+…+(1/2006-1/2011)]
=1/5*(1-1/2011)
=402/2011