Verified answer

Développer : F= 49-(3x+2)²

F = 49-9x²+12x+4

F = -9x²+12x+53

A =(3x+2)²

A = 9x²+12x+4

Factoriser : F = 49-(3x+2)²

F = 49-(3x+2)(3x+2)

F = 49-9x²+6x+6x+4

F = -9x²+12x+45

F pour x= 5/3

F = -9*5/3+12*5/3+45

F = -45/3+60/3+45

F = 15/3+45

F = 15/3+135/3

F = 150/3 = 50.

voilà :)

bonjour

1) factoriser F = 49 -(3x +2)² est de la forme de a²-b²= (a-b)(a+b) où a = 7 et b =3x+2

F = 7² -(3x+2)²

F = (7 -3x-2)(7+3x+2)

F = (5-3x)(9+3x) 

2) (a+b)² =a²+b²+2ab