Let's go:
[tex]\2x + y = 14 + y \\\ 2x = 14 \\\ x = 7 \\\ \frac{2x + y}{14 + y} = \frac{5x - y}{x + 13y}[/tex]
Changing x for 7:
[tex]\frac{2.7 + y}{14 + y} = \frac{5.7 - y}{7 + 13y} \\\\ \frac{14 + y}{14 + y} = \frac{35 - y}{7 + 13y} \\\\ \frac{35 - y}{7 + 13y} = 1 \\\\ 35 - y = 7 + 13y \\\ 14y = 28 \\\ y = 2[/tex]
I hope I helped you.
