Let $A$ and $B$ be subsets of a set $X$. Then
$A - B = A \cup B$
$A - B = A \cap B$
$A - B = {A^c} \cap B$
$A - B = A \cap {B^c}$
Using that for any sets $\mathrm{A}$ and $\mathrm{B},$
$A \cup(A \cap B)=A$
If $A \cap B = B$, then
Sets $A$ and $B$ have $3$ and $6$ elements respectively. What can be the minimum number of elements in $A \cup B$
If $X=\{a, b, c, d\}$ and $Y=\{f, b, d, g\},$ find
$X-Y$
Show that for any sets $\mathrm{A}$ and $\mathrm{B}$, $A=(A \cap B) \cup(A-B)$ and $A \cup(B-A)=(A \cup B).$