$$\frac{x+y-7}{3}=\frac{2x-y+1}{5}=\frac{3x+y-11}{7}$$
$\frac{x+y-7}{3}=\frac{2x-y+1}{5}\text{ and }\frac{2x-y+1}{5}=\frac{3x+y-11}{7}$
$x=2$
$y=5$
$y=5$
$x=2$
