Answer
a) $A\cup B=\{0,1,2,3,4,5,6\}$
b) $A \cap B=\{3\}$
c) $A-B=\{1,2,4,5\}$
d)$B-A=\{0,6\}$
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 $A\cup B=\{0,1,2,3,4,5,6\}$.
b) $A \cap B$ is the set of elements that are in both $A$ and $B$. So $A \cap B=\{3\}$
c) $A-B$ is the set of elements that are in $A$ but not in $B$. So $A-B=\{1,2,4,5\}$.
d)$B-A$ is the set of all elements that are in $B$ but not in $A$. So $B-A=\{0,6\}$.