Réponses

2013-02-10T17:25:39+01:00

f(x)= (3x+1)²-4x(2x+1) = (3x)²+2*3x*1+1²-4x*2x-4x*1 = 9x²+6x+1-8x²-4x =x²+2x+1 alors c'est x²