Répondre :
B = 5(1-x +2x(x-1))
= 5(1-x+2x(-1+x))
= 5(1-x-2x(1-x))
Factorisation
= 5(1-x)[1-2x]
= 5(1-x)(1-2x)
C = (x+4)² - (5+2x) ²
Identité : a² - b² = (a+b)(a-b)
= (x+4 - (5+2x))(x+4 + (5+2x))
= (x+4 - 5 - 2x) (x+4+5+2x)
= (1-x)(3x+9)
= (1-x)(3x + 3*3)
= 3 (1-x)(x + 3)
= 5(1-x+2x(-1+x))
= 5(1-x-2x(1-x))
Factorisation
= 5(1-x)[1-2x]
= 5(1-x)(1-2x)
C = (x+4)² - (5+2x) ²
Identité : a² - b² = (a+b)(a-b)
= (x+4 - (5+2x))(x+4 + (5+2x))
= (x+4 - 5 - 2x) (x+4+5+2x)
= (1-x)(3x+9)
= (1-x)(3x + 3*3)
= 3 (1-x)(x + 3)