3x+3+xy=18
3x+xy=15
3+y=15/x cautam printre divizorii lui 15 (1,3,5,15)
1. x=1 => 3+y=15/1, y=12
(x,y)=(1,12)
2. x=3 => 3+y=15/3=5, y=2
(x,y)=(3,2)
3. x=5 => 3+y=15/5=3, y=0
(x,y)=(5,0)
4. x=15 => 3+y=15/15=1
3+y=1 nu se poate
Deci perechile sunt (1,12), (3,2) si (5,0).
