Réponses

2012-12-06T21:06:44+01:00

D = (6x²+15x-2x-5) - (9x²-6x+1)

= 6x²+13x-5+9x²+6x-1 = 15x²+19x-6

 

si x ) 2 D = 15*2² + 19*2-6 = 15*4+38-6

= 60+38-6 = 98-6 = 92

j'ai oublié la factorisation

 

(3x-1)(2x+5)-(3x-1)

= (3x-1)(2x+5+3x+1)

= (3x-1)(5x+6)