Réponses

2013-04-05T16:12:17+02:00

E = 2x+8x²-4x- (3x²-9x+2x-6)

E = 2x +8x² -4x-3x²+9x-2x+6

E = 5x²-4x+6

 

pour x = 2

E = 20 -8+6 = 26-8 = 18