Answer
We need to show that every element of A × B is also an element of C × D. By definition, a typical element
of A × B is a pair (a, b) where a ∈ A and b ∈ B. Because A ⊆ C , we know that a ∈ C ; similarly, b ∈ D.
Therefore (a, b) ∈ C × D.
Work Step by Step
We need to show that every element of A × B is also an element of C × D. By definition, a typical element
of A × B is a pair (a, b) where a ∈ A and b ∈ B. Because A ⊆ C , we know that a ∈ C ; similarly, b ∈ D.
Therefore (a, b) ∈ C × D.
