Bonjour , vous pourriez m'aider ? Exercice 1: 1/ Factoriser les expressions suivantes : A= 5x (x-2) – x(x+ 2) B = (2x - 3)2 – (6x – 7)(2x - 3) C = 4(2a = 5)2 –

Bonjour.

Factoriser :

A = 5x(x-2)-x(x+2)

A = x(5(x-2)-(x+2))

A = x(5x-10-(x+2))

A = x(5x-10-x-2)

A = x(4x-10-2

A = x(4x-12)

A = x×4(x-3)

A = 4x(x-3)

B = (2x-3)2-(6x-7)(2x-3)

B = 2(2x-3)-(6x-7)(2x-3)

B = (2x-3)(2-(6x-7))

B = (2x-3)(2-6x+7)

B = (2x-3)(9-6x)

B = (2x-3)×3(3-2x)

B = 3(2x-3)(3-2x)

C = 4(2a-5)2-(2a-5)

C = 8(2a-5)-(2a-5)

C = 7(2a-5)

Développer puis réduire :

A = 5x(x-2)-x(x+2)

A = 5x²-10x-x(x+2)

A = 5x²-10x-x²-2x

A = 4x²-10x-2x

A = 4x²-12x

B = (2x-3)2-(6x-7)(2x-3)

B = (2x-3)(2-(6x-7)

B = (2x-3)(2-6x+7)

B = (2x-3)(9-6x)

B = (2x-3)(-6x+9)

B = (2x-3)(-3(2x-3))

B = (2x-3)(-3)(2x-3)

B = (2x-3)²(-3)

B = -(2x-3)²3

B = -3(2x-3)²

B = -3(4x²-12x+9)

B = -12x²+36x-27

C = 4(2a-5)2-(2a-5)

C = (4×2-1)(2a-5)

C = (8-1)(2a-5)

C = 7(2a-5)

C = 14a-35