Question

Intr-un bloc sunt apartamente cu 2 si cu 3 camere, in total fiind 41 de camere si 17 apatament. Calculati cate apartamente sunt cu 3 camere?Dar cu 2? DAU COROANA!!!

Answer 1

[tex]apartamentul~ cu~2 ~camere~ este~ x\\\\ apartamentul ~ cu~ 3~ camere ~este~ y\\\\ 2x+3y=41\\\\ x+y=17*2\\\\ 2x+2y=34\\\\ 41-3y=34-2y\\\\ 41-34=-2y+3y\\\\ y=7~ apartamente~ cu~ 3~ camere\\\\ 2x+21=41 \\\\ 2x=20\\\\ x=10~ apartamente~cu~ 2 ~camere.\\\\ Succes![/tex]

Answer 2

x+y=17   ;  x=17-y
2x+3y =41
2(17-y ) +3y  =41
34- 2y +3y =41
y =41-34
y =7   apartamente cu 3 camere
x =17-y
x =17-7 =10 ap. cu 3 camere
verif  ;  2*10+3*7 =20+21 =41 camere