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winner123
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Tu dois utiliser les identités remarquables dans certains cas.
A = (x-1)(x-1) +4(x+5)
A = (x-1)(x-1 +4x +20)
A = (x-1)(5x +19)

B = (2x +5)²
C = (3x+1-2)(3x+1+2)
C = (3x -1)(3x +3)

E = (x-2)(x+2) + (x-2)(2x+1)
E = (x-2)(x+2) +(2x+1)
E = (x-2)(x+2+2x+1)
E = (x-2)(3x +3)
D : pas certaine donc je préfère ne pas répondre
A = (x - 1)^2 + 4(x - 1)(x + 5) = (x - 1)(x - 1 + 4 x + 20) = (x - 1) (5 x + 19)
B = 4 x^2 + 20 x + 25 = (2 x)^2 + 2 (2 x) (5) + 5^2 = (2 x + 5)^2
C = (3 x + 1)^2 - 4 = (3 x + 1)^2 - 2^2 = (3 x + 1 - 2)(3 x + 1 + 2) = (3 x - 1)(3 x + 3) = 3 (3 x - 1)(x + 1)
D = 2 x - 3 + (2 x - 3)^2 = (2 x - 3)(1 + 2 x - 3) = (2 x - 3)(2 x - 2) = 2 (2 x - 3)(x - 1)
E = x^2 - 4 + (x - 2)(2 x + 1) = x^2 - 2^2 + (x - 2)(2 x + 1) = (x - 2)(x + 2) + (x - 2)(2 x + 1) = (x - 2)(x + 2 + 2 x + 1) = (x - 2) (3 x + 3) = 3(x - 2)(x + 1)

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