Đáp án: \(x<-2\) hoặc \(x>3\). Giải thích các bước giải: \(\begin{array}{l}\left( {3 – x} \right)\left( {x + 2} \right) < 0\\ \Rightarrow \left[ \begin{array}{l}\left\{ \begin{array}{l}3 – x > 0\\x + 2 < 0\end{array} \right.\\\left\{ \begin{array}{l}3 – x < 0\\x + 2 > 0\end{array} \right.\end{array} \right. \Rightarrow \left[ \begin{array}{l}\left\{ \begin{array}{l}x < 3\\x < – 2\end{array} \right.\\\left\{ \begin{array}{l}x > 3\\x > – 2\end{array} \right.\end{array} \right. \Rightarrow \left[ \begin{array}{l}x < – 2\\x > 3\end{array} \right.\end{array}\) Vậy \(x<-2\) hoặc \(x>3\). Trả lời
Đáp án:
\(x<-2\) hoặc \(x>3\).
Giải thích các bước giải:
\(\begin{array}{l}
\left( {3 – x} \right)\left( {x + 2} \right) < 0\\
\Rightarrow \left[ \begin{array}{l}
\left\{ \begin{array}{l}
3 – x > 0\\
x + 2 < 0
\end{array} \right.\\
\left\{ \begin{array}{l}
3 – x < 0\\
x + 2 > 0
\end{array} \right.
\end{array} \right. \Rightarrow \left[ \begin{array}{l}
\left\{ \begin{array}{l}
x < 3\\
x < – 2
\end{array} \right.\\
\left\{ \begin{array}{l}
x > 3\\
x > – 2
\end{array} \right.
\end{array} \right. \Rightarrow \left[ \begin{array}{l}
x < – 2\\
x > 3
\end{array} \right.
\end{array}\)
Vậy \(x<-2\) hoặc \(x>3\).