(1+3+5.+2009+2011)-(2+4+6...2010+2012=
问题描述:
(1+3+5.+2009+2011)-(2+4+6...2010+2012=
答
=(1-2)+(3-4)+(5-6)+.+(2009-2010)+(2011-2012)
=(-1)×1006
=-1006