Réponses

2013-03-07T20:18:38+01:00

9 - (2x - 1)^2

= 9 - (2x)^2 + 1^2 - 2(2x)(1)

= 9 - 4x^2 +1 -4x

= -4x^2 -4x +10

 

Fac:

2(-2x^2 -2x +5)