两个括号里的式子均为等差数列.所以不难算：(m+3m+5m+……+2009m)-(2m+4m+6m+……+2010m) =(m+2009m)×１００５／２－（２ｍ＋２０１０ｍ）×１００５／２ =1010025m-1011030m =-1005m