x/1/5=y/1/6=z/1/15=k
5x=k=>x=k/5
6y=k=>y=k/6
15z=k=>z=k/15
3k/5-2k/6-k/15=12 (Acum aducem la acelasi numitor, nc=30)
18k-10k-2k=360
6k=360
k=60
x=60:5=12
y=60:6=10
z=60:15=4
Facem o verificare:
3*12-2*10-4=12
36-20-4=12
16-4=12
12=12
Ajungem la concluzia ca rezultatele pe care le-am gasit sunt corecte
