Đáp án:
Giải thích các bước giải:
\[\begin{array}{l}
A = \left( {m - 1;4} \right],B = \left( { - 2;2m + 2} \right)\\
\Rightarrow \left\{ \begin{array}{l}
m - 1 < 4\\
- 2 < 2m + 2
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
m < 5\\
m > - 2
\end{array} \right.\\
a)\,\,A \cap B = \emptyset \Leftrightarrow 2m + 2 \le m - 1 \Leftrightarrow m \le - 3\\
Vay\,khong\,co\,m\,thoa\,man.\\
b)\,A \subset B \Leftrightarrow - 2 \le m - 1 < 4 < 2m + 2\\
\Leftrightarrow \left\{ \begin{array}{l}
- 2 \le m - 1\\
2m + 2 > 4
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
m \ge - 1\\
m > 1
\end{array} \right. \Leftrightarrow m > 1\\
Ket\,hop\, - 2 < m < 5\,ta\,duoc\,1 < m < 5\\
c)\,B \subset A \Leftrightarrow m - 1 \le - 2 < 2m + 2 < 4\\
\Leftrightarrow \left\{ \begin{array}{l}
m - 1 \le - 2\\
- 2 < 2m + 2\\
2m + 2 < 4
\end{array} \right. \Leftrightarrow \left\{ \begin{array}{l}
m \le - 1\\
m > - 2\\
m < 1
\end{array} \right. \Leftrightarrow - 2 < m \le - 1\\
Ket\,hop\, - 2 < m < 5\,ta\,duoc\, - 2 < m \le - 1
\end{array}\]
