Réponses

2013-05-19T16:30:54+02:00

Développer :

A=(x-6)²-(x-6)(5x+2)= x² - 12x + 36 - ( 5x² +2x -30x -12 )

                           = x² -12x +36 -5x² +28x +12

                           = -4x² +16x +48

Factoriser

(x-6)²-(x-6)(5x+2)= ( x-6) (x -6 -5x -2)

                                = (x -6) (-4x - 8)

Résoudre :

 

 (5x-12)(5x+6)=0

 5x -12 =0

5x=12

x = 12/5

 

5x +6=0

5x=-6

x = -6/5