以知A>0,B<0,简化la+bl-la-bl+l-a-bl-lb-al
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 01:46:51
![以知A>0,B<0,简化la+bl-la-bl+l-a-bl-lb-al](/uploads/image/z/4458581-53-1.jpg?t=%E4%BB%A5%E7%9F%A5A%EF%BC%9E0%2CB%EF%BC%9C0%2C%E7%AE%80%E5%8C%96la%2Bbl-la-bl%2Bl-a-bl-lb-al)
以知A>0,B<0,简化la+bl-la-bl+l-a-bl-lb-al
以知A>0,B<0,简化la+bl-la-bl+l-a-bl-lb-al
以知A>0,B<0,简化la+bl-la-bl+l-a-bl-lb-al
la+bl-la-bl+l-a-bl-lb-al
=la+bl-(a-b)+la+bl+(b-a)
=2la+bl-2(a-b)
a>-b =2a+2b-2a-+2b=4b
a<-b =-2a-2b-2a+2b=-4a