2 câu trả lời
`-5 + | 3x - 1 | + 6 = | -4 |`
`<=> -5 + | 3x - 1 | + 6 = 4`
`<=> -5 + | 3x - 1 | = 4 - 6`
`<=> -5 + | 3x - 1 | = -2`
`<=> | 3x - 1 | = -2 + 5`
`<=> | 3x - 1 | = 3`
`<=>` $\left[\begin{matrix}3x - 1 = 3\\ 3x - 1 = -3\end{matrix}\right.$
`<=>` $\left[\begin{matrix}3x = 4\\ 3x = -2\end{matrix}\right.$
`<=>` $\left[\begin{matrix}x = \dfrac{4}{3}\\ x = -\dfrac{2}{3} \end{matrix}\right.$
$Vậy$ `x ∈ { -2/3 ; 4/3 }`
Đáp án:
`-5+|3x-1|+6=|-4|`
`⇒-5+|3x-1|+6=4`
`⇒|3x-1|+1=4`
`⇒|3x-1|=3`
$⇒\left[\begin{matrix}3x-1=3\\ 3x-1=-3\end{matrix}\right.$
$⇒\left[\begin{matrix}3x=4\\ 3x=-2\end{matrix}\right.$
$⇒\left[\begin{matrix}x=\dfrac{4}{3}\\ x=\dfrac{-2}{3}\end{matrix}\right.$
Vậy `x∈{4/3;-2/3}`
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