If $\frac{x}{y}={\left(\frac{-1}{3}\right)}^{-3}÷{\left(\frac{2}{3}\right)}^{-4},\text{ then the value of }{(\frac{x}{y}+\frac{y}{x})}^{-1}\times {\left(\frac{y}{x}\right)}^{-1}\text{ is :}$