x+y+z=141
z=1/2 x
(y-x)/(x+z)=[3(x+z)+1]/(x+z)
Simplificam ec. 3 prin 1/(x+z) si obtinem y-x=3x+3z+1 de aici inlocuind in prima si atreia ecuatie z+1/2x obtinem
11x-2y=-2 si
3x+2y=282
rezolvam sistemul prin reducere si otinem
x=20 si z=10 de aici
y=141-30=111