X + Y + Z= 418
X = 2×Z
Y = X:4 - 2
X _____ _____ _____ _____
Y _____-2
Z _____ _____
avem 7 se gmente egale -2 = 418
418 + 2 = 420
420:7 = 60 (un segment)
X = 4× 60 = 240
Y = 60-2 = 58
Z = 2 × 60 = 120
Verificare:
240+58+120 = 418
Raspuns: 240 timbre (primul prieten)
58 timbre (al 2-lea prieten)
120 timbre (al 3-lea prieten)