Question

l2x-6l =x-7

Answer 1

Giải:

Có \(\left|2x-6\right|=x-7\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-6=x-7\\2x-6=-\left(x-7\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x-6=x-7\\2x-6=-x+7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-7+6\\3x=7+6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\3x=13\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{13}{3}\end{matrix}\right.\)

Vậy \(x=-1\) hoặc \(x=\dfrac{13}{3}\).

Chúc bạn học tốt!

Answer 2

l2x-6l =x-7

đk: \(x-7\ge0\Rightarrow x\ge7\forall x\) ( * )

\(\left[{}\begin{matrix}2x-6=x-7\\2x-6=-x+7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\3x=13\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-1\\x=\dfrac{13}{3}\end{matrix}\right.\)( ko t/m đk *)

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