Answer:
12x³ - 8x² - 54x - 36
Explanation:
The polynomial is the product of the factors, that is
(- 4x - 6)(- 3x² + 5x + 6)
Each term in the second factor is multiplied by each term in the first factor, that is
- 4x(- 3x² + 5x + 6) - 6(- 3x² + 5x + 6) ← distribute both parenthesis
= 12x³ - 20x² - 24x + 18x² - 30x - 36 ← collect like terms
= 12x³ - 8x² - 54x - 36