Cho A ⊂ B, B ⊂ C thì?

cho A⊂ B,B⊂C thì:
a, A∪ (B/C)
b, A /(B∩ C)
c,(A∩ C)∪B
d,(A/C) ∩B
e,(A∪ B)∩ C
f,(A∩ C) (B∩ C)