Réponse :
Bonjour,
Développer:
[tex](x + 1)(2x + 3) - (x + 5)(x + 1)\\\\= 2x^2 + 3x + 2x + 3 - (x^2 + x + 5x + 5)\\\\= 2x^2 + 3x + 2x + 3 - x^2 - x - 5x - 5\\\\= 2x^2 - x^2 + 3x + 2x - x - 5x + 3 - 5\\\\= x^2 - x - 2[/tex]
Factoriser:
[tex](x + 1)(2x + 3)-(x+5)(x+1)\\\\= (x + 1)[(2x + 3) - (x + 5)]\\\\= (x + 1)(2x + 3 - x - 5)\\\\= (x + 1)(x - 2)[/tex]
