Answer:
x² + 9x + 15
Step-by-step explanation:
Given
(2x + 3)² - 3(x - 1)(x + 2) ← expand factors using FOIL
= 4x² + 12x + 9 - 3(x² + x - 2) ← distribute
= 4x² + 12x + 9 - 3x² - 3x + 6 ← collect like terms
= x² + 9x + 15
