1. A = {(1,3), (2,4), (-4,-8), (3,9), (1,5), (3,6), (1,2), (6,30)}, R is defined on A as follows: for all (a, b), (c, d) Î A,

(a, b) R (c, d) Û ad = bc.

[(1,3)] = {(1,3), (3,9)}

[(2,4)] = {(2, 4), (-4, -8), (1, 2), (3, 6)}

[(1,5)] = {(1, 5), (6, 30)}

2. A = {0, 1, 2, 3, 4}
   R = {(0,0), (0,2), (0,4), (1,1), (1,3), (2,0), (2,2), (3,1), (3,3), (4,0), (4,4)}
   Is R reflexive? __YES__
   Is R symmetric? _YES__
   Is R transitive? __NO __, If not find the transitive closure of R: {(2, 4), (4, 2)}
   
   List the distinct equivalence classes of R (union the transitive closure elements if needed). Include all the members in each class:
   
   [0] = {0, 2, 4}
   
   [1] = {1, 3}