Answer:
8x³ - 2x² - 51x - 45
Explanation:
Given
(x - 3)(2x + 3)(4x + 5) ← expand second/third factors using FOIL
= (x - 3)(8x² + 22x + 15) ← distribute
= x(8x² + 22x + 15) - 3(8x² + 22x + 15) ← distribute parenthesis
= 8x³ + 22x² + 15x - 24x² - 66x - 45 ← collect like terms
= 8x³ - 2x² - 51x - 45