Step-by-step explanation:
(x-3)(2x+1)(x+1)
(2x² - 6x + x - 3)(x+1)
(2x² - 5x - 3) (x+1)
2x³ -5x² -3x + 2x² -5x - 3
2x³ - 3x² - 8x -3
