\(\left|3x-4\right|=3x-4\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-4=3x-4\\3x-4=-3x+4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-3x=-4+4\\3x+3x=4+4\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}0x=0\\6x=8\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{4}{3}\end{matrix}\right.\)
Vậy ..
\(\left|3x-4\right|=3x-4\)
\(\Rightarrow\left[{}\begin{matrix}3x-4=3x-4\\3x-4=-3x+4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}3x+3x=4+4\\3x-3x=-4+4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}6x=8\\0x=0\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{4}{3}\\x=0\end{matrix}\right.\)
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