Question 146807
{{{x^2 + (x-y)^2 = (x+y)^2}}}
{{{x^2 + x^2 -2xy + y^2 = x^2 + 2xy + y^2}}}
{{{2x^2 -2xy = x^2 + 2xy}}}
{{{x^2 = 4xy}}}
x = 4y