Répondre :
• (3x-1)² - (2x+1)²
=(5x)(x-2)
• (x-2) (2x+5) + 4(x-2)(x-1)
=(x-2)(6x+1)
• (2x-5)² + (x+7)(5-2x)
=(5x-5)(x-12)
• (2x-1)² -3 (2x-1)(x+2)
=(2x-1)(-x-7)
=(5x)(x-2)
• (x-2) (2x+5) + 4(x-2)(x-1)
=(x-2)(6x+1)
• (2x-5)² + (x+7)(5-2x)
=(5x-5)(x-12)
• (2x-1)² -3 (2x-1)(x+2)
=(2x-1)(-x-7)