4. Решите уравнение 12-(4-x)² = x (3 - x).

$$12 - (4-x)^2 = x(3-x)$$ $$12 - (16 - 8x + x^2) = 3x - x^2$$ $$12 - 16 + 8x - x^2 = 3x - x^2$$ $$-4 + 8x - x^2 - 3x + x^2 = 0$$ $$5x - 4 = 0$$ $$5x = 4$$ $$x = \frac{4}{5}$$ Ответ: $$x = \frac{4}{5}$$