Réponses

2013-03-14T14:46:58+01:00

(2x-1)²+(2x-1)(-x-3)

=(2x-1) [(2x-1)+( -x-3)]

=(2x-1) (x-4)

2013-03-14T14:47:54+01:00

   (2x + 1) [(2x + 1) - (x - 3)]

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

= (2x + 1) (x + 4).