Réponses

2014-02-12T18:20:23+01:00
(3x-5)² -(3x-5) (12x+4) 
=(3x-5)(3x-5-12x-4)
=(3x-5)(-9x-9)
=9(3x-5)(-x-1)

( 6x-5) (4x+7) +(6x-5)(2x-5) 
=(6x-5)(4x+7+2x-5)
=(6x-5)(6x+2)
=2(6x-5)(3x+1)

(3x-2)(6x+7) - (3x-2) (-2x+4) 
=(3x-2)(6x+7+2x-4)
=(3x-2)(8x+3)

(6x -8)² - (2x-3)²
=[6x-8-(2x-3)][6x-8+(2x-3)]
=(6x-8-2x+3)(6x-8+2x-3)
=(4x-5)(8x-11)