Răspuns:
1. AXB= { (-2,0); (-1,0); (3,0) ; (-2,2) ; (-1,2) ;(3,2)}
BXA={ (0,-2), (0,-1) , (0,3) ,(2,-2), (2, -1), (2,3)}
AXA= { (-2, -2), (-1,-1), (3,3)}
BXB= { (0,0), (2,2)}
2. D={ -2, -1, 0, 1,2}
CXD= { (-3,-2),( -3,-1), (-3,0), (-3,1), (-3,2), (1, -2), (1, -1), (1,0), (1, 1), (1,2)}
3. A={ -4, -2}
B={ 0, 2, 4, 6}