(m+3m+5m+……+2009m)-(2m+4m+6m+……+2010m)求大神帮助

将括号打开，可以得m-2m+3m-4m+5m-6m+...+2009m-2010m (m-2m)+(3m-4m)+....+(2009m-2010m) =-m-m-m-m....-m(2010两个有一个m，所以有1005个m) =－1005m

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