Réponses

2012-10-04T20:18:02+02:00

Bonsoir,

 

a) (3x+1)²+9x²-1 = 9x²+6x+1+9x²-1

                          = 18x² + 6x

                          = 6x(3x+1)

 

 

b) (2x-3)(3x+7)-2x+3 = 6x²+14x-9x-21-2x+3

                                = 6x²+3x-18

                                = 3(2x²+x+6)

 

c) (5x-4)²-5x+4 = 25x²-40x+16-5x+4

                        = 25x²-45x+20

                        = 5(5x²-9x+4)