[tex]\bf ~~~~~~~~~~~~\textit{negative exponents}\\\\
a^{-n} \implies \cfrac{1}{a^n}
\qquad \qquad
\cfrac{1}{a^n}\implies a^{-n}
\qquad \qquad
a^n\implies \cfrac{1}{a^{-n}}\\\\
-------------------------------\\\\
\cfrac{16r^8zm^4}{2r^5z^6m^3}\implies \cfrac{16}{2}\cdot \cfrac{r^8r^{-5}m^4m^{-3}}{z^6z^{-1}}\implies \cfrac{8}{1}\cdot \cfrac{r^{8-5}m^{4-3}}{z^{6-1}}\implies \cfrac{8r^3m}{z^5}[/tex]