Simplify the complex fraction 1x+1y1x2−1y2\frac{\frac{1}{x} + \frac{1}{y}}{\frac{1}{x^2} - \frac{1}{y^2}}x21−y21x1+y1.
xyy−x\frac{xy}{y-x}y−xxy
xyx−y\frac{xy}{x-y}x−yxy
x−yxy\frac{x-y}{xy}xyx−y
x+yx+yx+y