It seems like you are defining two sets, $A$ and $B$, but there is no specific question attached. Let's explore a few operations that can be performed with these sets:

1. Union: The union of sets $A$ and $B$ is the set of all elements that are in $A$, in $B$, or in both. $A \cup B = \{2, 4, 6, 7, 8\}$

2. Intersection: The intersection of sets $A$ and $B$ is the set of elements that are in both $A$ and $B$. Since there are no common elements: $A \cap B = \emptyset$

3. Difference: The difference $A - B$ (elements in $A$ but not in $B$) is: $A - B = \{7, 8\}$ And the difference $B - A$ (elements in $B$ but not in $A$) is: $B - A = \{2, 4, 6\}$

4. Cartesian Product: The Cartesian product $A \times B$ is the set of all ordered pairs where the first element is from $A$ and the second is from $B$: $A \times B = \{(7, 2), (7, 4), (7, 6), (8, 2), (8, 4), (8, 6)\}$

Let me know if you have any specific operations or questions related to these sets, or if you'd like further details.

Relative Questions:

1. What is the union of two sets and how is it useful in set theory?
2. How can we find the Cartesian product of sets, and what are its applications?
3. What is the difference between set intersection and set union?
4. How do you interpret an empty set result in an intersection?
5. How does the difference operation work between two sets?

Tip: When working with sets, remember that the order of elements in the set does not matter, but each element must be unique.