、大家帮下忙哈 .
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:综合作业 时间:2024/08/19 11:45:40
、大家帮下忙哈 .
![](http://img.wesiedu.com/upload/e/7c/e7caa96f1c18cde99a95cdd8369c1f56.jpg)
![](http://img.wesiedu.com/upload/e/7c/e7caa96f1c18cde99a95cdd8369c1f56.jpg)
![、大家帮下忙哈 .](/uploads/image/z/3978723-3-3.jpg?t=%E3%80%81%E5%A4%A7%E5%AE%B6%E5%B8%AE%E4%B8%8B%E5%BF%99%E5%93%88+.)
1.(1)AB:BC=1:2 (2)AC:AB=3:1 (3)BC:AC=2:3
2.AD:BD=AE:CE -> BD:AD=CE:AE -> (AB+AD):AD=(AC+CE):AE -> AB:AD=AC:AE
-> AD:AB=AE:AC -> AB*AE=AD*AC -> AB:AC=AD:AE
3.x+y:y=7:2
4.a=12 b=16 c=20
2.AD:BD=AE:CE -> BD:AD=CE:AE -> (AB+AD):AD=(AC+CE):AE -> AB:AD=AC:AE
-> AD:AB=AE:AC -> AB*AE=AD*AC -> AB:AC=AD:AE
3.x+y:y=7:2
4.a=12 b=16 c=20