Answer:
12x³ - 7x² + 11x + 14
Step-by-step explanation:
Each term in the second factor is multiplied by each term in the first factor, that is
3x(4x² - 5x + 7) + 2(4x² - 5x + 7) ← distribute both parenthesis
= 12x³ - 15x² + 21x + 8x² - 10x + 14 ← collect like terms
= 12x³ - 7x² + 11x + 14
