Exercițiul 11 va rog

A={1,2,3,4}-->2·12=24(nu depaseste 55)
3·12=36
4·12=48
B={1,2,3,4,5,6,7}
AUB={1,2,3,4,5,6,7}
AnB(u intors)={1,2,3,4}
A/B=faza e ca B are tot ce are A
B/A={5,6,7}
Sper ca e corect....SUCCES!