1. **State the problem:** We have two sets $A = \{x, y, z, w\}$ and $B = \{x, y\}$. We need to determine which of the following statements are true:
- $B \not\subseteq A$
- $A \not\subseteq B$
- $B \subseteq A$
- $A \subseteq B$
2. **Recall definitions:**
- $X \subseteq Y$ means every element of set $X$ is also in set $Y$ (subset).
- $X \not\subseteq Y$ means there is at least one element in $X$ not in $Y$.
3. **Check each statement:**
- $B \not\subseteq A$? Since $B = \{x, y\}$ and $A = \{x, y, z, w\}$, all elements of $B$ are in $A$. So $B \subseteq A$ is true, thus $B \not\subseteq A$ is false.
- $A \not\subseteq B$? $A$ has elements $z$ and $w$ which are not in $B$. So $A \subseteq B$ is false, hence $A \not\subseteq B$ is true.
- $B \subseteq A$? As above, all elements of $B$ are in $A$, so this is true.
- $A \subseteq B$? Since $z$ and $w$ are in $A$ but not in $B$, this is false.
4. **Final answers:**
- $B \not\subseteq A$: False
- $A \not\subseteq B$: True
- $B \subseteq A$: True
- $A \subseteq B$: False
Therefore, the true statements are $A \not\subseteq B$ and $B \subseteq A$.
Subset Relations 22E933
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