Respuesta :

Answer:

a =  y - x.

Step-by-step explanation:

ax + x^2 = y^2 - ay

ax + ay = y^2 - x^2

a (x + y) = y^2 - x^2

a =   (y^2 - x^2) / (x + y)

a = (y + x)(y - x) / (x + y)

a =  y - x Answer.