2:
a) A U B= {1,2,4,5,6,7}
b) B U A={1,2,4,5,6,7}
c) A inter. B ={2}
d) B inter. A={2}
e) A\B={1,5,7}
f) B\A={4,6}
5:
a) A U B={1,2,3,5}
b) B inter. C= {1,5}
c) A\C= {2}
d) A U (C\B)= A U {4,6}= {1,2,4,6}
e) (A inter. B) U (B inter. C)= {1} U {1,5}= {1,5}
f) se repeta punctul e)
g) se repeta punctul e)...este dubios
h) A inter. (B U C)= A inter. {1,3,4,5,6}= {1}
i) A\A= Ø
j) (A\B) U (B\A)= {2} U {3,5}= {2,3,5}
k) (A U B)\(A inter. B)= {1,2,3,5}\{1}= {2,3,5}
l) A inter. B inter. C= {1}
