Réponses

2014-10-20T11:08:59+02:00


x² + x- 2x -2 - (2x ²+ 2x +6 x +6)

x²+ x- 2x- 2- 2x²- 2x- 6x -6

x²- 2x² +x -2x  -2x -6x -6-2

x² -9x -8

2014-10-20T11:11:28+02:00
(x-2)(x+1) - (2x+6) (x+1)
 = (x^2 + x - 2x - 2) - (2x^2 + 2x +6x + 6)
= (x^2 - x - 2 )  - (2x^2 +8x + 6)
= x^2 - x -2 - 2x^2 -8x -6 
= -x^2 - 9x - 8