1/2*4+1/4*6+1/6*8+...+1/2012*2014=
问题描述：
1/2*4+1/4*6+1/6*8+...+1/2012*2014=
1/2是怎么的来的?
答
=1/2*(1/2-1/4+1/4-1/6+1/6-1/8+……+1/2012-1/2014)
=1/2*(1/2-1/2014)
=503/2014