8.Fie multimile:A={x∈N*|x ≤ 4};B={x ∈ N|2 ≤ x ≤ 3};C={x∈N*|3x+1 < 10. a)Enumerati elementele multimilor A,B,C. b)Calculati: A U B,A U C,B U C,A ∩ B,A ∩ C,B ∩ C,A - B,B - A,A - C,C - A,B - C, C - B,(A U B) ∩ C, (A ∩ B) U C,(A - B) U(B - A),A U B U C,A ∩ B ∩ C,(A - B) ∩ C,(A U B) - C,(A ∩ B) - A, (A - C) ∩ (C - A).