Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=x^{-6}$, $a^m=x^{-4}$, $a=x$, $a^m/a^n=\frac{x^{-4}y^{-2}}{x^{-6}y^{-3}}$, $m=-4$ e $n=-6$

Applicare la formula: $\frac{a^m}{a^n}$$=a^{\left(m-n\right)}$, dove $a^n=y^{-3}$, $a^m=y^{-2}$, $a=y$, $a^m/a^n=\frac{x^{2}y^{-2}}{y^{-3}}$, $m=-2$ e $n=-3$