Réponses

2013-10-21T18:36:39+02:00
25x-15
=5(5x-3)

(9x+2)(2x-5)+(9x+2)(2-9x)
=(9x+2)(2x-5+2-9x)
=(9x+2)(-7x-3)

(5x-1)(3x+2)+(5x-1)(5x+1)
=(5x-1)(3x+2+5x+1)
=(5x-1)(8x+3)