Réponses

2013-11-05T22:41:17+01:00
4x²-4x+1 = (2x-1)^{2}

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

(x-2)(2x+5)+4(x-2)(x-1)
 = 
(x-2) ( (2x+5)+4(x-1) )   = (x-2) ( 2x+5+4x-4)
 =(x-2) (6x + 1 )
2013-11-06T00:11:41+01:00
4x²-4x+1 = ?
Forme a^2-2ab +b^ = (a-b)^2  donc   = 

(3x-1)²-(2x+1)² = ?
forme a^2 - b^2 = (a+b) (a-b)  donc =  = ( x-2) (5x)

(x-2)(2x+5)+4(x-2)(x-1)
 =