Simplify x2−y2x2+2xy+y2\frac{x^2 - y^2}{x^2 + 2xy + y^2}x2+2xy+y2x2−y2.
x−yx+y\frac{x-y}{x+y}x+yx−y
x+yx−y\frac{x+y}{x-y}x−yx+y
−1-1−1
1x+y\frac{1}{x+y}x+y1