On considere la fonction f definie sur Rpar f(x)=x(x+4)-(3x+2)(x+4) 1.Determiner les images de a=2 b= -1 c=2/3 d=√3 2.Factoriser f(x) 3.Developper f(x) 4.En ded

2/

x(x+4)-(3x+2)(x+4)

(x+4)(x-3x-2)

(x+4)(-2x-2)

3/

x²+4x -(3x²+12x+2x+8)

x²+4x-3x²-14x-8

-2x²-10x-8

4/

(x+4)(-2x-2) = 0

x+4 =0                -2x-2 =0

x = -4                       -2x = 2

x= -4                             x -2/2 = -1

donc antecedent (-4 ; -1)

(x+4)(-2x-2) = -8

x+4 = -8                              -2x-2 = -8

x= -8-4                                       -2x = -8+6

x = -12                                      -2x = -2

x = -12                                         x = -2/-2 = 1