Réponse :
Explications :Pour 1) votre réponse est juste .
2) A = (x - y)/(x + y) + (y^2 )/(x + y)^2 = (x^2 - y^2)/(c + y)^2 + (y^2)/(x + y)^2 = (x^2 - y^2 + y^2)/(x + y)^2 = (x^2)/(x + y)^2 = (x/(x + y))^2
