Answer
$\{a,e,i,o,u\}$
Work Step by Step
Our goal is to find the union of the two given sets:
$\{a,e,i,o,u\}\cup \emptyset$
To find the union, we first list the elements of the first set: $a,e,i,o,u$. Next, we list the elements of the second set. In this case, the second set is the empty null set, which has no elements. Thus, the elements common to both sets include all of the elements from the first set: $a,e,i,o,u$. The result is the union:
$\{a,e,i,o,u\}\cup \emptyset=\{a,e,i,o,u\}$
