#### Answer

$A\cup B=\{a,b,c,d,e\}$

#### Work Step by Step

$A=\{a,b,c\}$ $;$ $B=\{a,c,d,e\}$
$A\cup B$
The union of two sets is a set formed by all the elements included in both sets.
The union of $A$ and $B$ has all the elements included in $A$ and all the elements included in $B$, as follows:
$A\cup B=\{a,b,c,d,e\}$