(-1)+3+(-5)+7+(-9)+11……+(-2007)+2009(1/1X3)+(1/2X5)+.+(1/2003X200_数学解答

(-1)+3+(-5)+7+(-9)+11……+(-2007)+2009
(1/1X3)+(1/2X5)+.+(1/2003X2005)
(1/1X4)+(1/4X7)+(1/7X10)+.(1/2002)X(1/2005)

人气：463 ℃　时间：2019-11-06 05:56:04

解答

(-1)+3+(-5)+7+(-9)+11……+(-2007)+2009
=-1+3 -5+7 -9+11..-2007+2009
=2+2+2+2+2+2+2+2+2+2+2++2+2+2+.+2
=502*2
=1004
(1/1X3)+(1/2X5)+.+(1/2003X2005)
=1002/2005
(1/1X4)+(1/4X7)+(1/7X10)+.(1/2002)X(1/2005)
=668/2005