分解因式（1）（4x²+5x)²-(5x+16)²

(4x² + 5x)² - (5x + 16 )²= (4x² + 5x + 5x +16)(4x² + 5x - 5x - 16)= (4x² + 10x + 16)(4x² - 16)= 8(x + 2)(x - 2)(2x² + 5x + 8)