Réponses

2013-03-14T17:16:46+01:00

 (2x+5)(3x-1)

= 6x^2 - 2x  + 15x - 5

= 6x^2 + 13x - 5

 

(x-1)^2 +x ^2+(x+1)^2

= x^2 -2x + 1 + x^2 + x^2 + 2x + 1

= 3x^2 + 2

 

 

 

 

2013-03-14T17:20:46+01:00

D = 6x²-2x+15x-5 = 6x²+13x-5

E = (x-1)² + x² +  (x+1)² = x²-2x+1+x²+x²+2x+1 = 3x² +2