Bonjour, voici comment procéder.
Réponse :
a.
A = (x - 1)(2 + 3x) - (x - 1)
A = (x-1)*(2+3x-1)
A = (x-1)*(1+3x)
A = x+3[tex]x^{2}[/tex]-1-3x
A = -2x+3[tex]x^{2}[/tex]-1
A = 3[tex]x^{2}[/tex]-2x-1
A = 3[tex]x^{2}[/tex]-2x-1
b.
A = (x - 1)(2 + 3x) - (x - 1)
A = (x-1)*(2+3x-1)
A = (x-1)*(1+3x)
A = (x-1)*(1+3x)
