x³ - 12x² + 41x - 30
x³ - 8x² + 5x + 50
x⁴ + 2x³ - 3x² - 4x +4
x³ - x² + 9x - 9
(x - 1)2 (x + 2)²
(x + 2)(x - 5)²
(x - 1)(x - 5)(x - 6)
(x - 1)(x² + 9)