(2x + 3y)^2 – 3x (\(\frac{4}{3}\) x + 4y) = 4x^2 + 12xy + 9y^2 - 4x^2 - 12xy = 9y^2
9y^2 = 9 * (\(\sqrt{3}\))^2 = 9 * 3 = 27
Ответ: 27