1/1x2+1/3x4+1/4x5+L+1/2008x2009第一个份数和第二个份数之间是少了1/2x3这个数的
问题描述：
1/1x2+1/3x4+1/4x5+L+1/2008x2009
第一个份数和第二个份数之间是少了1/2x3这个数的
答
原式=1-1/2+1/3-1/4+1/4-1/5+……+1/2008-1/2009
=1-1/2+1/3-1/2009
=10039/12054
答
=1-1/2+1/2-1/3+1/3-1/4+...+1/2008-1/2009
=1-1/2009
=2008/2009
答
原式=1-1/2+1/3-1/4+1/4-1/5+……+1/2008-1/2009
=1-1/2+1/3-1/2009
=10039/12054