1/1x2+1/2x3+1/3x4+.+1/2008x2009=?题中X是乘号/请详细说明所得成果/谢谢~

问题描述:

1/1x2+1/2x3+1/3x4+.+1/2008x2009=?题中X是乘号/请详细说明所得成果/谢谢~

=(1/1-1/2)+(1/2-1/3)+...+(1/2008-1/2009)=2008/2009