Answer
$\dfrac{y^3}{x^3}$
Work Step by Step
RECALL:
(1) $(a^m)^n=a^{mn}$
(2) $(ab)^m=a^mb^m$
(3) $a^{-m} = \dfrac{1}{a^m}, a \ne 0$
(4) $a^1 = a$
Use rule (2) above to obtain:
$=(x^{-1})^3y^{3}$
Use rule (1) above to obtain
$=x^{(-1)\cdot3}y^{3}
\\=x^{-3}y^{3}$
Use rule (3) above to obtain
$=\dfrac{1}{x^3} \cdot y^3
\\=\dfrac{y^3}{x^3}$
