[tex]x - y = \frac{3}{7} *350 \\ x-y= \frac{1050}{7} \\ x-y=150 \\ \\ \frac{3}{4} * (x+y)=570 \\ x+y=570: \frac{3}{4} \\ x+y=570* \frac{4}{3} \\ x+y= \frac{2280}{3} \\ x+y=760 \\ \\ \left \{ {{x+y=760} \atop {x-y=150}} \right. =\ \textgreater \ 2x =910 =\ \textgreater \ x=455 \\ \\ y=760-455 =\ \textgreater \ y=305[/tex]