Appendix A - Review - A.1 Algebra Essentials - A.1 Assess Your Understanding - Page A12: 98

$\displaystyle \frac{y^{3}}{x^{3}}$

Apply rule $\quad(ab)^{n}=a^{n}b^{n}$ $(x^{-1}y)^{3}=(x^{-1})^{3}\cdot(y^{3})\quad$ Apply rule $\quad (a^{m})^{n}=a^{mn}$ $=x^{-3}y^{3} \quad$. Apply rule $\displaystyle \quad a^{-n}=\frac{1}{a^{n}}$ $=\displaystyle \frac{1}{x^{3}} \cdot y^3 \\=\displaystyle \frac{y^{3}}{x^{3}}$