Set contain all the elements present in both the sets.
<u>Step-by-step explanation:</u>
Definition:
The union of two mathematical sets can be defined as the set that consists of all the elements present in both the sets without the repetition of elements.
Consider, A and B be the sets.
A = {1,7,5,6,0}
B = {2,3,4,5,6}
U is the symbol of union of sets, so A U B = {1,2,3,4,5,6,7,0}
Here 5 and 6 are the elements present in both the sets, so written only once in the set of A U B.