Question

(2x-1)(x-2)≤0

Answer 1

\(\left(2x-1\right)\left(x-2\right)\le0\)

\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}2x-1\ge0\\x-2\le0\end{matrix}\right.\\\left\{{}\begin{matrix}2x-1\le0\\x-2\ge0\end{matrix}\right.\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge\dfrac{1}{2}\\x\le2\end{matrix}\right.\\\left\{{}\begin{matrix}x\le\dfrac{1}{2}\\x\ge2\end{matrix}\right.\end{matrix}\right.\) \(\Leftrightarrow\dfrac{1}{2}\le x\le2\) ( Do : \(\left\{{}\begin{matrix}x\le\dfrac{1}{2}\\x\ge2\end{matrix}\right.\) vô lý )

KL.............

Answer 2

Phạm Thanh TườngPhùng Khánh Linh