Question

1.FIE A={1A6B IN BAZA ZECE /1A6B DIVIZIBIL CU 5 SI 4/(a+b)};B={1X6X IN BAZA ZECE /1X6X DIVIZIBIL CU 2}CALCULATI.AUB,AnB,A-B,B-A,ATRIUNGHIB.
2.DETERMINATI MULTIMILE A SI B CARE INDEPLINESC CONDITIILE : AUB={1,2,3,4}
AnB={2,3} A-B={1}.
3.FIE A={X/X E N,7<5X-2<17}},B={X /Y E N*,Y<3}.CALCULATI.AUB,AnB.A-B,B-A ,ATRIUNGHIB. DAU COROANA !!! REPEDE ...

Answer 1

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}