求1\1X2+1\2X3+1\3X4+1\4X5.+1\2009X2010的值,请帮我解答,

问题描述:

求1\1X2+1\2X3+1\3X4+1\4X5.+1\2009X2010的值,请帮我解答,
抱歉,刚才那道题写错了,应该是1\1X2+1\2X3+1\4X5+1\6X7+...1\2009X2010,实在是sorry,

1\1X2+1\2X3+1\3X4+1\4X5.+1\2009X2010
=1-1/2+1/2-1/3+……+1/2009-1/2010
=1-1/2010
=2009/2010