Show that if A ⊂ B, then C – B ⊂ C – A.
Question:
Show that if A ⊂ B, then C – B ⊂ C – A.
Solution:
Let A ⊂ B
To show: C – B ⊂ C – A
Let x ∈ C – B
⇒ x ∈ C and x ∉ B
⇒ x ∈ C and x ∉ A [A ⊂ B]
⇒ x ∈ C – A
∴ C – B ⊂ C – A