Réponse :
factoriser
D = (2 x - 1)(1 - 3 x)+(7 x - 4)(2 - 6 x) + (9 x - 3)(5 x + 1)
= (2 x - 1)(1 - 3 x) + 2(1 - 3 x)(7 x - 4) - 3(1 - 3 x)(5 x + 1)
= (1 - 3 x)(2 x - 1 + 2(7 x - 4) - 3(5 x + 1))
= (1 - 3 x)(2 x - 1 + 14 x - 8 - 15 x - 3)
= (1 - 3 x)(x - 12)
H = (6 x - 5)(3 x - 1) - 9 x²+ 6 x - 1
= (6 x - 5)(3 x - 1) - (9 x²- 6 x + 1)
= (6 x - 5)(3 x - 1) - (3 x - 1)²
= (3 x - 1)(6 x - 5 - 3 x + 1)
= (3 x - 1)(3 x - 4)
Explications étape par étape
