Question

How to solve 2X^2+Y^2 = X^2-Y^2

Answer 1

   
$2x^2+y^2 = x^2-y^2\\\\ 2x^2 - x^2 + y^2 + y^2 = 0\\\\ x^2 + 2y^2=0\\\\ x^2 = 0~~~\Longrightarrow~~~\boxed{x=0}\\\\ 2y^2 = 0~~~\Longrightarrow~~~y^2 = 0~~~\Longrightarrow~~~\boxed{y=0}$