\(\sqrt{x^2-2x+1}+\sqrt{9x^2-6x+1}=3\)
\(\Leftrightarrow\sqrt{\left(x-1\right)^2}+\sqrt{\left(3x-1\right)^2}=3\)
\(\Leftrightarrow\left|x-1\right|+\left|3x-1\right|=3\)
\(\Leftrightarrow\left|x-1\right|=3-\left|3x-1\right|\)
pt <=> \(\left[{}\begin{matrix}x-1=3-3x+1\\x-1=3+3x-1\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{4}\left(tm\right)\\x=-\dfrac{3}{2}\left(ktm\right)\end{matrix}\right.\)
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