\(\frac{x^2}{y^2}+\frac{y^2}{x^2}-\frac{x}{y}-\frac{y}{x}\)
\(=\frac{x^2-xy}{y^2}+\frac{y^2-xy}{x^2}\)
\(=\frac{x^4-x^3y+y^4-xy^3}{x^2y^2}\)
\(=\frac{x^3\left(x-y\right)-y^3\left(x-y\right)}{x^2y^2}\)
\(=\frac{\left(x-y\right)^2\left(x^2+xy+y^2\right)}{x^2y^2}\)