Answer:
3x³ - 13x² + 7x - 12
Step-by-step explanation:
Each term in the second factor is multiplied by each term in the first factor, that is
x(3x² - x + 3) - 4(3x² - x + 3) ← distribute both parenthesis
= 3x³ - x² + 3x - 12x² + 4x - 12 ← collect like terms
= 3x³ - 13x² + 7x - 12
