[tex]x\to nr. \ apartamentelor \ cu \ 2 \ camere \\ y\to nr. \ apartamentelor \ cu \ 4 \ camere \\\\ \left \{ {{x+y=60} \ \ |(-2) \atop {2x+4y=190}} \right. \\\\\\ \left \{ {{-2x-2y=-120} \atop {2x+4y=190}} \right.\\ ========== \\\\ / \ \ \ 2y=70 \ |:2 \ \ \ \ \to \boxed{y=35} \\\\ x+y=60 \\\\ x=60-y \\\\ x=60-35 \\\\ \boxed{x= 25}[/tex]
OR
[tex]x\to nr. \ apartamentelor \ cu \ 2 \ camere \\ y\to nr. \ apartamentelor \ cu \ 4 \ camere \\\\ x+y=60 \ \ \ \ \to \boxed{x=60-y} \\\\ 2x+4y=190 \\\\ 2(60-y)+4y=190 \\\\ 120-2y+4y=190 \\\\ 2y=190-120 \\\\ 2y=70 \ |:2 \\\\ \boxed{\boxed{y=35}} \\\\ x=60-35 \\\\ \boxed{\boxed{x=25}}[/tex]
