Réponse :
Explications étape par étape
Bonjour
Factoriser :
(x-3)(2x+5)-(3-x)(3x+1)
= (x - 3)(2x + 5) + (x - 3)(3x + 1)
= (x - 3)(2x + 5 + 3x + 1)
= (x - 3)(5x + 6)
1-x^2+(4x+3)(x-1)-(5x+2)(1-x)
= (1 - x)(1 + x) + (4x + 3)(x - 1) - (5x + 2)(1 - x)
= (1 - x)(1 + x) - (4x + 3)(1 - x) - (5x + 2)(1 - x)
= (1 - x)(1 + x - 4x - 3 - 5x - 2)
= (1 - x)(-8x - 4)
= (1 - x) * (-4)(2x + 1)
= -4(1 - x)(2x + 1)
(4x^2+20x+25)-(9x^2-6x+1)
= (2x)^2 + 2 * 2x * 5 + 5^2 - [(3x)^2 - 2 * 3x + 1^2]
= (2x + 5)^2 - (3x - 1)^2
= (2x + 5 - 3x + 1)(2x + 5 + 3x - 1)
= (-x + 6)(5x + 4)