1. Find the power set of A, where A = { 2x ? Z | 7 < x < 10, x ? Z }.

2. For all sets A and B, simplify the given expression,

(A ? (A ? B)) ? (B ? (A ? B))

Cite a property from Theorem 6.2.2 for every step of the proof.

3. Let, A={3n ? Z | -1? n ? 3, n ? Z } , B={1, 2} and C = {{1,2}}. Find A X ( B X C) .

4. Use an element argument to prove the statement:

For all sets A and B, A^c ? B^c ? (A ? B)^c.