devoir de maths. merci =). Développer en utilisant l’identité remarquable qui convient : A = (x + 4)²   B = (2 – x)²    C = (x + 1)(x – 1)    D = (2x + 1)²   E

A=(x+4)²=x²+8x+16
B=(2-x)²=4-4x+x²
C=(x+1)(x-1)=x²-x+x-1=x²-1
D=(2x+1)²=4x²+4x+1
E=(3-2x)²=9-12x+4x²
F=(7x+5)²=49x²+70x+25
G=(5x+6)(5x-6)=25x²-30x+30x-36=25x²-36
H=(4-8x)²=16-64x+64x²
I=(3+4x)(3+4x)=9+12x+12x+16x²=9+24x+16x²
J=(3+x)(x-3)=3x-9+x²-3x=9+x²
K=(2+9x)²=4+36x+81x²
L=(11x-12)²=121x²-264x+144

Bonjour

A = (x + 4)²  = x² +8x +16

 B = (2 – x)² = 4 - 4x +x²

 C = (x + 1)(x – 1)  = x² -1

 D = (2x + 1)²  = 4x² +4x +1
 E = (3 – 2x)² = 9 - 12x +4x²
  F = (7x + 5)²   = 49x² + 70x +25
 G = (5x + 6)(5x – 6)  = 25x² - 36
   H = (4 – 8x)²  = 16 - 64x + 64x²
 I = (3 + 4x)(3 + 4x)  = 9 + 12x + 12x + 16x² = 16x² +24x +9
  J = (3 + x)(x – 3)     =3x -9 +x² -3x = x² -9
 K = (2 + 9x)²   = 4 + 36x + 81x²
  L = (11x – 12)²  = 121x² - 264 x + 144