Answer:
X\Y={3,12}
Explanation:
Given the sets X and Y below:
[tex]\begin{gathered} X=\mleft\{3,8,9,12\mright\} \\ Y=\mleft\{8,9\mright\} \end{gathered}[/tex]The set X\Y is the set of elements in X but not in Y.
Therefore:
[tex]X\Y=\mleft\{3,12\mright\}[/tex]