Réponses

2014-02-09T17:59:19+01:00
A=(X+3)²= x²+6x+9 
B=(6X-5)²= 36x²-60x+25
C=(7X-10)(7X+10)= 49x²-100
D=4X+5)(6X-3)-4(X+2)=24x²-12x+30x-15-4x-8
                                    = 24x²+14x-23