4. Решите уравнение: 1) 3x³ - 12x = 0; 2) 49x³ + 14x² + x = 0; 3) x³ - 5x² - x + 5 = 0.

1) 3x³ - 12x = 0 3x(x² - 4) = 0 3x(x - 2)(x + 2) = 0 x = 0, x = 2, x = -2 2) 49x³ + 14x² + x = 0 x(49x² + 14x + 1) = 0 x(7x + 1)² = 0 x = 0, x = -1/7 3) x³ - 5x² - x + 5 = 0 x²(x - 5) - (x - 5) = 0 (x² - 1)(x - 5) = 0 (x - 1)(x + 1)(x - 5) = 0 x = 1, x = -1, x = 5