Question

dau cel mai inteligent raspuns . intr-un bloc sunt in total 60 de apartamente de 2 si 4 camere. aflati cate apartamente de fiecare fel sunt,daca blocul are 190 de camere.

Answer 1

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


$x\to nr. \ apartamentelor \ cu \ 2 \ camere \\ y\to nr. \ apartamentelor \ cu \ 4 \ camere \\\\ x+y=60 \ \ \ \ \to \boxed{x=60-y} \\\\ 2x+4y=190 \\\\ 2(60-y)+4y=190 \\\\ 120-2y+4y=190 \\\\ 2y=190-120 \\\\ 2y=70 \ |:2 \\\\ \boxed{\boxed{y=35}} \\\\ x=60-35 \\\\ \boxed{\boxed{x=25}}$

Answer 2

60 * 4 = 240 camere
240 - 190 = 50 camere
50 : 2 = 25 apartamente cu 2 camere
190 - 50 = 140 camere
140 : 4 = 35 apartamente cu 4 camere