化简|5x+根号x²|（x＜0）.

化简|5x+根号x²|（x＜0）.
化简|5x+根号x²|（x＜0）.

化简|5x+根号x²|（x＜0）.
因为x＜0
所以|x |=-x
又因为根号x²= |x |
|5x+根号x²|
=|5x+|x| |
= |5x-x |
= |4x |
=-4x