For any two sets A and B, prove that: A’ – B’ = B – A
To show, A’ – B’ = B – A
We need to show
A’ – B’ ⊆ B – A
B – A ⊆ A’ – B’
Let, x ϵ A’ – B.’
⇒ x ϵ A’ and x ∉ B.’
⇒ x ∉ A and x ϵ B
⇒ x ϵ B – A
It is true for all x x ϵ A’ – B’
∴ A’ – B’ = B – A
Hence Proved.