(2+4+6+8+10+12....+100)-(1+3+5+7+9+11...+99)解：=2+4+6+8+10+12....+100-1-3-5-7-11-99 =(2-1)+(4-3)+(6-5)...+(100-99) =1+1+1+1+1+1+...+1 =50×1 =50有帮助采纳！有疑问追问！
