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 ?

Hint: Look at:
$$\left(\frac{x}{y} + \frac{y}{x}\right)^2=3^2=9$$
Why to look at this? We know if we expand we will have a $(\frac{x}{y})^2=\frac{x^2}{y^2}$ term and a $(\frac{y}{x})^2=\frac{y^2}{x^2}$ term so this might be worth a try.
