Simplify x4−y4x2−y2÷(x2+y2)\frac{x^4-y^4}{x^2-y^2} \div (x^2+y^2)x2−y2x4−y4÷(x2+y2).
x2−y2x^2-y^2x2−y2
000
111
x2+y2x^2+y^2x2+y2