Răspuns:
2,5x=0,5y=5z=k
x=2,5k
y=0,5k
z=5k
2,5k+0,5k+5k=78
8k=78=>k=78:8=>k=9,75
x=2,5·9,75=>x=24,375
y=0,5·9,75=>y=4,875
x=5·9,75=>z=48,75
