What is the union of the sets that include nine?
So here we have a set and its only element is nine. And here we have another set and its only element is nine. Now, this symbol looks like a U. And it stands for the union of the two sets. And the union of two sets should include the elements that are in either set or are in both sets.
So they each have element nine. Which means the union of those two sets would have to be nine. Because nine is in both sets. And there aren’t any elements in either set that aren’t in the other. And we would have listed those. However, we don’t have any. So this will be our final answer.