U - Reuniune, toate el puse laolata o singura data
A U B = B U A
U intors - il notez cu W - Intersectie -> ce e in prima dar si in a doua
A W B = B W A
- este scaderea, ce este in prima dar nu si in a doua
ATENTIE!
A - B NU = B - A
A = { -8/7, -11/5, 1, 2} 2.2 = 22/10 = 11/5, 4/2 = 2
B = {-29/5, -11/5, 7/10, 1, 2} 5.8 = 58/10 = 29/5, 0,7 = 7/10
A W B = {-11/5, 1 , 2 }
B W Z = { 1, 2}
A U B = {-29/5, -8/7, -11/5, 7/10, 1, 2}
A - B = {-8/7}
B - A = {-29/5, 7/10}
A - Z = { -8/7, -11/5 }
