Question

Tìm x biết:

\(\left(x-6\right)\left(x-4\right)< 0\)

Answer 1

\(\left(x-6\right)\left(x-4\right)< 0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x-6>0\\x-4< 0\end{matrix}\right.\\\left\{{}\begin{matrix}x-6< 0\\x-4>0\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x>6\\x< 4\end{matrix}\right.\\\left\{{}\begin{matrix}x< 6\\x>4\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}6< x< 4\left(loai\right)\\4< x< 6\left(chon\right)\end{matrix}\right.\)

Vậy \(4< x< 6\)