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