To find the union and intersection of two sets, you need to:
List all elements from the first set.
Add the elements from the second set.
Cross out any repetitions (i.e., leave one copy of each).
For every element, check if it's in the sets:
The union gathers those that appear in at least one; and
The intersection gathers those that appear in both.
Enjoy having found the union and intersection of two sets.
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