va rog la mate ex 4 si 5 va rog

4.
A={1,2,3,4,...,16}
B={1,2,3,4}
A intersectat cu B ={1,2,3,4}
AUB={1,2,3,4,..,16}
A\B={5,6,7,8,...,16}
B\A={O(multimea vida)}