4. Решите уравнение: 1) 2x³ - 50x = 0; 2) 16x³ + 8x² + x = 0; 3) x³ + 2x² - 36x - 72 = 0.

**Решение:** 1) ( 2x^3 - 50x = 0 ) ( 2x(x^2 - 25) = 0 ) ( 2x(x - 5)(x + 5) = 0 ) ( x = 0, x = 5, x = -5 ) 2) ( 16x^3 + 8x^2 + x = 0 ) ( x(16x^2 + 8x + 1) = 0 ) ( x(4x + 1)^2 = 0 ) ( x = 0, x = -\frac{1}{4} ) 3) ( x^3 + 2x^2 - 36x - 72 = 0 ) ( x^2(x + 2) - 36(x + 2) = 0 ) ( (x^2 - 36)(x + 2) = 0 ) ( (x - 6)(x + 6)(x + 2) = 0 ) ( x = 6, x = -6, x = -2 )