Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
3.14\\
\left| x \right| < 3 \Leftrightarrow - 3 < x < 3 \Rightarrow A = \left( { - 3;3} \right)\\
\left| x \right| \ge 2 \Leftrightarrow \left[ \begin{array}{l}
x \ge 2\\
x \le - 2
\end{array} \right. \Rightarrow B = \left( { - \infty ; - 2} \right] \cup \left[ {2; + \infty } \right)\\
\Rightarrow A \cap B = \left( { - 3; - 2} \right] \cup \left[ {2;3} \right)\\
A\backslash B = \left( { - 2;2} \right)\\
B\backslash A = \left( { - \infty ; - 3} \right] \cup \left[ {3; + \infty } \right)\\
3.15\\
\left| {x - 2} \right| \ge 1 \Leftrightarrow \left[ \begin{array}{l}
x - 2 \ge 1\\
x - 2 \le - 1
\end{array} \right. \Leftrightarrow \left[ \begin{array}{l}
x \ge 3\\
x \le 1
\end{array} \right. \Rightarrow A = \left( { - \infty ;1} \right] \cup \left[ {3; + \infty } \right)\\
\left| {x - 1} \right| < 1 \Leftrightarrow - 1 < x - 1 < 1 \Leftrightarrow 0 < x < 2 \Rightarrow B = \left( {0;2} \right)\\
A \cap B = \left( {0;1} \right]\\
A\backslash B = \left( { - \infty ;0} \right] \cup \left[ {3; + \infty } \right)\\
B\backslash A = \left( {1;2} \right)
\end{array}\)
