Răspuns:
3. A reunit cu B={1,2,3,5,6}
A intersectat cu B={2,5}
A minus B={1,6}
B minus A={3}
4. A={1,3,5,7}
B={2,4,5,7}
C={4,6,7,9}
A reunit cu B={1,2,3,4,5,7}
A reunit cu C={1,3,5,7,4,6,9}
B reunit cu C={2,4,5,7,9}
A minus B={1,3}
A minus C={1,3,5}
B minus C={2,5}
A reunit cu B reunit cu C={1,2,3,4,5,6,7,9}
A intersectat cu B intersectat cu C={7}
(A reunit cu C) minus B={1,3,6,9}
