If a = - 8, b = -7, c = 6, verify that (a + b) + c = a + (b + c).

If A = {1, 2, 3,4}, B= {2, 4,6, 8} and C= { 3, 4, 5,6}, verify that : A nn (B nn C)= (A nn B) nn C .

Let A = {1,2} ,B = {1,2 ,3,4 } ,c={5,6} and d={5,6,7,8 } verify that A xx ( B nn C ) = (A xx B ) nn (A xx C )

If A = {1, 2, 3}, B= { 4, 5, 6} and C= { 7, 8, 9}, verify that : A uu (B nn C)= (A uu B) nn (A uu C) .

If a, b, c, d satisfy the equation a + 7b + 3c + 5d = 0 , 8a + 4b + 6c + 2d = - 16 , 2a + 6b + 4c + 8d =16 and 5a + 3b + 7c + d = -16 then the value of (a + d) (b + c) =______

Let A= {1, 2}, B = {1, 2, 3, 4}, C = {5, 6} andD = {5, 6, 7, 8}. Verify that A xx (B nn C) = (A xx B) nn (A xx C) .

If A={1,2,4, 5}, B= {2, 3, 5, 6} and C = (4, 5, 6, 7}, then verify that : A nn (B-C)= (A nn B)- (A nn C) .

Let A= {1, 2}, B = {1, 2, 3, 4}, C = {5, 6} andD = {5, 6, 7, 8}. Verify that A xx C is a subset of B xx D .