developpement & factorisations justes ?

[inviteb6953e61]

Pourriez-vous m'aider svp ? Developpement:

B=(1-x)²-2(x-5)(1-4x)
=1²-2*1x+x²-2(1x-4x²-5+20x)
=1-2x+x²-2x+8x²+10-40x
=11-44x+9x²

C=3(2x-1)²-2(2-x)²
=3[(2x)²-2*2x*1+1²]-2(2²-2*2*x+x²)
=12x²-12x+1-8+8x+x²
=13x²-4x-7

Factorisations :

C= (x+2)(5x-1)-(5x+2)(x+2)
=(x+2)[(5x-1)-(5x+2)]
=(x+2)(5x-1-5x-2)
=(x+2)(0x-3)

D=(2x+3)²-(2x+3)(-4x+2)
=(2x+3)[(2x+3)-(-4x+2)]
=(2x+3)(2x+3+4x-2)
=(2x+3)(6x+1)

E=4x²-1-(2x-1)(3x+5)
=(2x-1)(2x-1)-(2x-1)(3x+5)
=(2x-1)[(2x+1)-(3x+5)]
=(2x-1)(2x+1-3x-5)
=(2x-1)(-x-4)

merci d'avance !
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[inviteb6953e61]

Sivvouplaiiiiii C Pour Demainnnnnn

[inviteb6953e61]

Juste pour ces deux developpement :
Sont-ils justes ??

B=(1-x)²-2(x-5)(1-4x)
=1²-2*1x+x²-2(1x-4x²-5+20x)
=1-2x+x²-2x+8x²+10-40x
=11-44x+9x²

C=3(2x-1)²-2(2-x)²
=3[(2x)²-2*2x*1+1²]-2(2²-2*2*x+x²)
=12x²-12x+1-8+8x+x²
=13x²-4x-7

[invitee3b6517d]

B=(1-x)²-2(x-5)(1-4x)
=1²-2*1x+x²-2(1x-4x²-5+20x)
=1-2x+x²-2x+8x²+10-40x
=11-44x+9x²

BON

C=3(2x-1)²-2(2-x)²
=3[(2x)²-2*2x*1+1²]-2(2²-2*2*x+x²)
=12x²-12x+1-8+8x+x²
=13x²-4x-7

FAUX

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Factorisations :

C= (x+2)(5x-1)-(5x+2)(x+2)
=(x+2)[(5x-1)-(5x+2)]
=(x+2)(5x-1-5x-2)
=(x+2)(0x-3)

BON

D=(2x+3)²-(2x+3)(-4x+2)
=(2x+3)[(2x+3)-(-4x+2)]
=(2x+3)(2x+3+4x-2)
=(2x+3)(6x+1)

BON

E=4x²-1-(2x-1)(3x+5)
=(2x-1)(2x-1)-(2x-1)(3x+5)
=(2x-1)[(2x+1)-(3x+5)]
=(2x-1)(2x+1-3x-5)
=(2x-1)(-x-4)

BON

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Et un merci ?