Question

9 carti si 8 caiete costa 167 lei, iar 2 carti si 4 caiete costa 64 lei. Cati lei plateste Diana daca cumpara 3 carti si 7 caiete de acelasi fel?
Ajutooooor

Answer 1

carti=x
caiete=y
9x+8y=167
2x+4y=64
9x+8y-(2x+4y)=7x+4y=167-64=103
7x-4y-2x-4y=5x=39
5x=39 ==> x= 39/5 =7.8lei
x=7.8lei
2x+4y=64
7.8*2+4y=64
4y=64-15.6
4y=48.4lei ==> y=12.1 lei
x=7.8lei
y=12.1lei
Verificare: 7.8*9+12.1*8=70.2+96.8=167 lei
==> 3carti+7caiete= 7.8*3 + 12.1*7=23.4 + 84.7= 108.1lei
Sper ca te-am ajutat :D