Which transformation maps x2−y2=nx^2 - y^2 = nx2−y2=n to a form useful for solving via divisors?
(x−y)(x+y)=n(x-y)(x+y) = n(x−y)(x+y)=n
(x−y)2=n(x-y)^2 = n(x−y)2=n
x2=n+y2x^2 = n + y^2x2=n+y2
x=n+y2x = \sqrt{n+y^2}x=n+y2