Bonjour Pouvez vous m'aide svp à factoriser ces expressions? A=(2x-1)(3-x)+(3-x)(4-7x) B=4x²-28x+49 C=(7x-8)(3x-5)-(2x+7)(7x-8)

Bonjour Chris243,

factoriser ces expressions?
A=(2x-1)(3-x)+(3-x)(4-7x)
A = (3 - x)(2x - 1 + 4 - 7x)
A = (3 - x)(-5x + 3)

B=4x²-28x+49
B = (2x)^2 - 2 * 2x * 7 + 7^2
B = (2x - 7)^2

C=(7x-8)(3x-5)-(2x+7)(7x-8)
C = (7x - 8)(3x - 5 - 2x - 7)
C = (7x - 8)(x - 12)

Coucou,

A =(2x-1) (3-x) + (3-x) (4-7x)
=(3-x) (2x-1+4-7x)
=(3-x) (-5x+3)

B=4x²-28x+49
=(2x)² - 2*2x*7+7²
=(2x-7)²

C=(7x-8)(3x-5)-(2x+7)(7x-8)
=(7x-8)(3x-5-2x-7)
=(7x-8)(x-12)

Voilà!