[tex]x-z= \frac{1}{4} y \\ x-70=y=z-52 \\ \\ 4(x-z)=y \\ x-70=4(x-z) \\ x-70=4x-4z \\ 4z-3x=70 \\ \\ x-70=z-52 \\ x-z=18/*3 \\ 3x-3z=54 \\ \\ 4z-3x+3x-3z=70+54 \\ z=124 \\ x=z+18=124+18 =142 \\ y=x-70=142-70=72 \\ \\ Verificare:x-z=\frac{1}{4} y;142-124= \frac{72}{4}; 18=18[/tex]