Verified answer

x²-81 =(x-9)(x+9)   identite remarquable de la forme a²-b² =(a-b)(a+b)

9t²-16 = (3t-4)(3t+4)  idem

x²+2x+1 =(x+1)²   identite a²+2ab+v² =(a+b)²

x²-6x+9 =(x-3)²   indentite a²-2ab+b =(a-b)²

Verified answer