Ответ:

[tex] \frac{x - y}{x + y} = \frac{2}{3} \\ 3(x - y) = 2(x + y) \\ 3x - 3y = 2x + 2y \\ 3x - 2x = 2y + 3y \\ x = 5y \\ \frac{x}{y} = 5 \\ {( \frac{x}{y}) }^{2} = {5}^{2} \\ \frac{ {x}^{2} }{ {y}^{2} } = 25[/tex]