We can solve this problem by using Venn Diagram In a Venn Diagrams, the universal set is usually represented by a rectangular region and its subsets by closed bounded regions (usually by circles or ellipses) inside this rectangular region. An element of a set is represented by a point within the region representing that set. The common region between the two circles (representing sets A and B) represent A ∩ B.
Excluding the portion of B from the region of A, we get the region representing (A - B).
Excluding the portion of A from the region of B, we get the region representing (B - A).
By using these definitions we can find the answer
From the figure it is clear that (A – B)∪(B – A)∪(A∩B) = A∪B