Question

1) .| 3+ 1 | - 2 = 0 giúp mình với

Answer 1

`|3x+1|-2=0`

`=>|3x+1|=2`

`=>`\(\left[ \begin{array}{l}3x+1=2\\3x+1=-2\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}3x=1\\3x=-3\end{array} \right.\) 

`<=>` \(\left[ \begin{array}{l}x=\dfrac13\\x=-1\end{array} \right.\) 

Vậy `x=1/3` hoặc `x=-1`

Answer 2

Ta có: |3x+1|-2=0

nên |3x+1|=2

\(\Leftrightarrow\left[{}\begin{matrix}3x+1=2\\3x+1=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=1\\3x=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=-1\end{matrix}\right.\)