Quelqu'un peut m'aider à réduire et ordonner les équations suivantes, en détail?

A= (x+1)(x-1)
B= (y+3)(y-3)
C= (-a+1)(-a+1)
D= (x+3)(x-3)
E=(-x+2)(-x+2)+(-2x+1)(x+1)
F= (-5a+1)(a-1)+(a+1)(a+3)
G=(4y+1)(-y+4)+(-2y+5)(4y-1)

voilàààà merci ! :)

2

Réponses

2013-11-25T17:42:52+01:00
A= (x+1)(x-1)
=x²-1

B= (y+3)(y-3)
=y²-3²
=y²-9

C= (-a+1)(-a+1)
=(-a)²-1
=a²-1

D= (x+3)(x-3)
=x²-3²
=x²-9

E=(-x+2)(-x+2)+(-2x+1)(x+1)
=x²-2x-2x+4+(-2x²)-2x+x+1
=-x²-5x+5

F= (-5a+1)(a-1)+(a+1)(a+3)
=-5a²+5a+x-1+a²+3a+a+3
=-4a²+10a+2

G=(4y+1)(-y+4)+(-2y+5)(4y-1)
=-4y²+16y-y+4+(-8y²)+2y+20y-5
=-12y²+37y-1
erreur dans le C:
C=(-a+1)(-a+1)=a²-a-a+1=a²-2a+1
2013-11-25T17:45:57+01:00
A = (x+1)(x-1)
   =x²-x+x-1=x²-1
B = (y+3)(y-3)
   =y²-3y+3y-9=y²-9
C = (-a+1)(-a+1)
   =a²-a-a+1=a²-2a+1
D = (x+3)(x-3)
   =x²-3x+3x-9=x²-9
E = (-x+2)(-x+2)+(-2x+1)(x+1)
   =(x²-2x-2x+4)+(-2x²-2x+x+1)
   =-x²-5x+5
F = (-5a+1)(a-1)+(a+1)(a+3)
   =-5a²+5a+a-1+a²+3a+a+3
   =-4a²+10a+2
G = (4y+1)(-y+4)+(-2y+5)(4y-1)
   =-4y²+16y-y+4+(-8y²+2y+20y-5)
   =-12y²+37y-1