Find $\frac{x^2}{y^2}$ + $\frac{y^2}{x^2}$ If $\frac{x}{y}$ + $\frac{y}{x}$ = 3 Find $\frac{x^2}{y^2}$ + $\frac{y^2}{x^2}$ 
Any Ideas on how to begin ?

\begin{align*}
\frac{x}{y} + \frac{y}{x} = 3 &\Longrightarrow \left(\frac{x}{y} + \frac{y}{x}\right)^2 = 9 \\
&\Longrightarrow \frac{x^2}{y^2} + \frac{y^2}{x^2} = 9-2=7
\end{align*} 
