Réponses

2013-04-16T13:46:18+02:00

D = (2x-3)(5-x)+(2x-3)²

= 10x-2x²-15+3x +4x²-12x+9

= 2x²+x--6

 

D = (2x-3)(5-5x)+(2x-3)

= 2x-3)(5-5x+2x-3)

= (2x-3)(7x+2)

 

(2x-3)(7x+2) = 0

soit 2x-3 = 0 donc 2x = 3 et x = 3/2

soit 7x+2 = 0 donc 7x = -2 et x = -2/7