|2x+6|-x=3
<=> |2x+6|= 3+x
<=> 2x+6= 3+x hoặc 2x+6= -3-x
<=> x= -3
\(\Leftrightarrow\left|2x+6\right|=x+3\left(x\ge-3\right)\Rightarrow2x+6=x+3\Leftrightarrow x=-3\left(TM\right)\)
Ta có: |2x+6|=x+3
\(\Leftrightarrow\left[{}\begin{matrix}2x+6=x+3\left(x\ge-3\right)\\2x+6=-x-3\left(x< -3\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\left(nhận\right)\\3x=-3-6=-9\end{matrix}\right.\Leftrightarrow x=-3\)
Vậy: S={-3}
| 2x + 6 | - x = 3
⇔ | 2x + 6 | = 3 + x
⇔\(\left\{{}\begin{matrix}2x+6=-\left(3+x\right)\\2x+6=3+x\end{matrix}\right.\)↔\(\left\{{}\begin{matrix}x=-3\\x=-3\end{matrix}\right.\)
⇒ x = \(-3\)
Vậy \(x=-3\)
| 2x+6 |-x=3
|2x+6| = x+3
TH1: x+3≥0 ⇔x≥-3 TH2: x+3<0 ⇔x<-3
2x+6=x+3 2x+6=-x-3
⇔ x=-3(tm) ⇔3x=-9 ⇔x=-3(ktm)
vậy S={-3}