1)
1a6b divizibil cu 5 ⇒ b este 0 sau 5
daca 1a60 si 4/(a+0)⇒ a∈{0,4,8}
daca 1a65 si 4/(a+5)⇒ a∈{3,7}
A={1060,1460, 1860,1365,1765}
B={1060,1262,1464,1666,1868}
AUB={1060,1460, 1860,1365,1765,1262,1464,1666,1868}
A n B={1060}
A-B={1460, 1860,1365,1765}
B-A= {1262,1464,1666,1868}
2.
A={2,3,4}
B={2,3,1}
3.
7<5x-2<17 /-2
5<5x<15 /:5
1<x<3 ⇒ A={2}
B={1,2}
AUB={1,2}
AnB={2}
A-B= Ф
B-A={2}