Answer
a) $A\cup B=\{a,b,c,d,e,f,g,h\}$
b) $A \cap B=\{a,b,c,d,e\}$
c) $A-B=\emptyset$
d) $B-A=\{f,g,h\}$
Work Step by Step
a) $A \cup B$ is the set of all elements that are in $A$, or in $B$, or in both $A$ and $B$. So $A\cup B=\{a,b,c,d,e,f,g,h\}$.
b) $A \cap B$ is the set of elements that are in both $A$ and $B$. So $A \cap B=\{a,b,c,d,e\}$
c) $A-B$ is the set of elements that are in $A$ but not in $B$. Since every element of $A$ is an element of $B$, there are no elements in $A$ that are not in $B$. So $A-B=\emptyset$.
d) $B-A$ is the set of all elements that are in $B$ but not in $A$. So $B-A=\{f,g,h\}$.
