Réponses

2014-10-05T11:33:35+02:00
À= (x+7-6)(x+7+6) → à²-b²=(a-b)(à+b)
A= (x+1)(x+13)

B= (2x+2)²=4(x+1)²

C= (x+1)[(x+13)-4(x+1)]
C= (x+1)(x+13-4x-4)
C= (x+1)(9-3x)

C=A-B