1. **Stating the problem:** Given two sets $A$ and $B$ with $A \subseteq B$, determine the sets $A - B$ and $B - A$. 2. **Recall definitions:** - The difference $A - B$ is the set of elements in $A$ that are not in $B$. - The difference $B - A$ is the set of elements in $B$ that are not in $A$. 3. **Important rule:** If $A \subseteq B$, then every element of $A$ is also in $B$. Therefore, $A - B = \emptyset$ because there are no elements in $A$ that are outside $B$. 4. **Apply to the first problem (1.A):** - $A = \{ x \mid x \in \mathbb{Z}, x \text{ is odd}, x \leq 3 \} = \{..., -3, -1, 1, 3\}$ - $B = \{ x \mid x \in \mathbb{Z}, -4 \leq x \leq 1 \} = \{-4, -3, -2, -1, 0, 1\}$ 5. **Check if $A \subseteq B$:** - $3 \in A$ but $3 \notin B$ (since $B$ only goes up to 1). - So $A \not\subseteq B$. 6. **Calculate $A - B$:** - Elements in $A$ not in $B$ are $\{3\}$. 7. **Calculate $B - A$:** - Elements in $B$ not in $A$ are $\{-4, -2, 0\}$. **Final answers:** $$A - B = \{3\}$$ $$B - A = \{-4, -2, 0\}$$