1. Use set identities or different proof method to show that: a) (B–A)U(C – A) = (BUC)-A b) (A-C)n(C − B) = Ø

Which of the following operations on the set Z has more than one left neutral element and at least one right neutral element? (a) a°b = b - a (b) a°b = b (c) a°b = a + ab - 1 (d) a ° b = ab (e) Such prescription does not exist.

# 2. Prove that for all sets A and B, (A - B) N B = Ø. Proof (A Proof By Contradiction):

(3) Given a non-empty (a) A# is isotone; set X and A, B C PX, show that: (b) ACB⇒ B# C A#; (c) If B is isotone and B# C A# then A C B; (d) A## = A¹; (e) (A¹)# = A#.

Let A = {1, 2, 3, 4), B = {1, 3, 5) and C = {2, 4, 5). Find: A × B|, |P(A × (B N C))|, |P(A × P(B))|, IP(P(A × Ø))| X X

suppose A = {a, b, c}. Mark the statement T or F {b, c} ∈ P(A){{a}} ⊆ P(A) ∅ ⊆ A{∅} ⊆ P(A)∅ ⊆ A × A {a, c} ∈ A{a, b} ∈ A × A (c, c) ∈ A × A

Let . Show that is in for all values of h and k (Be sure to explain what your work tells you! I shouldn’t be interpreting computations).