Question

Answer 1

ĐKXĐ: \(\left(4x-6\right)\left(9-3x\right)\ge0\)

\(\Leftrightarrow\left(x-\dfrac{3}{2}\right)\left(3-x\right)\ge0\)

\(\Rightarrow\dfrac{3}{2}\le x\le3\)

Hay \(D=\left[\dfrac{3}{2};3\right]\)

Answer 2

Hàm số xác định `<=> (4x-6)(9-3x)>=0`

`<=>` \(\left[{}\begin{matrix}\left\{{}\begin{matrix}4x-6\ge0\\9-3x\ge0\end{matrix}\right.\\\left\{{}\begin{matrix}4x-6\le0\\9-3x\le0\end{matrix}\right.\end{matrix}\right.\)

`<=>` \(\left[{}\begin{matrix}\left\{{}\begin{matrix}x\ge\dfrac{3}{2}\\x\le3\end{matrix}\right.\\\left\{{}\begin{matrix}x\le\dfrac{3}{2}\\x\ge3\end{matrix}\right.\end{matrix}\right.\)

`<=>` \(\left[{}\begin{matrix}\dfrac{3}{2}\le x\le3\\VN\end{matrix}\right.\)

Vậy `S=[3/2 ; 3]`.