Answer:
The set A' is defined as [tex]A'=\{1,5,7,11,17,19,21\}[/tex].
Step-by-step explanation:
The universal set is
[tex]U=\{1,3,5,7,9,11,13,15,17,19,21\}[/tex]
Set A is given,
[tex]A=\{3,9,13,15\}[/tex]
A' means the set of all elements of universal set except the elements of set A.
[tex]A'=U-A[/tex]
[tex]A'=\{1,3,5,7,9,11,13,15,17,19,21\}-\{3,9,13,15\}[/tex]
[tex]A'=\{1,5,7,11,17,19,21\}[/tex]
Therefore the set A' is defined as [tex]A'=\{1,5,7,11,17,19,21\}[/tex].