Réponses

2014-01-09T17:09:57+01:00
N= (4x-5)((x-3)-(3x+1))=(4x-5)(x-3-3x-1)=(4x-5)(-2x-4)=-2(4x-5)(x+2)

x1=5/4, x2=-2
2014-01-09T17:18:46+01:00
(4x-5)(x-3)-(3x+1)(4x-5)=
(4x-5)(x-3-3x-1)=
(4x-5)(-2x-4)=
je développe
-8x^2-8x-10x-20=
je factorise
-2x (8x-19)