Question

\(\left|5x-4\right|=\left|x+2\right|\)

Answer 1

\(\left|5x-4\right|=\left|x+2\right|\)

\(\Leftrightarrow\left[{}\begin{matrix}5x-4=x+2\\5x-4=-x-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}5x-x=2+4\\5x+x=-2+4\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}4x=6\\6x=2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

Answer 2

\(\left|5x-4\right|=\left|x+2\right|\)

\(\Rightarrow\left\{{}\begin{matrix}5x-4=x+2\\5x-4=-x-2\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}5x-x=2+4\\5x+x=-2+4\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}4x=6\\6x=2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{1}{3}\end{matrix}\right.\)

Vậy..........

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