What is the result of simplifying 1x2−y2÷1x−y\frac{1}{x^2-y^2} \div \frac{1}{x-y}x2−y21÷x−y1?
1x+y\frac{1}{x+y}x+y1
x+yx+yx+y
x−yx-yx−y
1x−y\frac{1}{x-y}x−y1