Bonjour
developper :
A = (2x + 3)^2 - (2x + 1)(2x - 1)
A = 4x^2 + 12x + 9 - (4x^2 - 1)
A = 4x^2 + 12x + 9 - 4x^2 + 1
A = 12x + 10
resoudre : A = 0
12x + 10 = 0
12x = -10
x = -10/12
x = -(2 * 5)/(2 * 6)
x = -5/6
