Réponse :

A= 5x(2x-4)+4x = 10x carré-20x++ 4

= 10x carré-16x

 = 2x(5x-8)

B=7x-(6x+4) =7x-6x-4 = x-4

C= (5x-8)(6x+7) = 30x carré +35x-48x-5

 = 30x carre-13x-56

D=(12x-5)(12x+5) = 144xcarre-2

E=7(3x+1)carré = 7(9xcarré + 6x+1)

 =63xcarré +42x+7

F=(2x-1)carre-(6x-2)(6x+2)

 =4xcarre-4x+1-(carré

 =4xcarre -4x+1-36xcarre +4

 =-32xcarre-4x+