Respuesta :
[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}}\\\\
-------------------------------\\\\
(9c^{-9})^{-3}\impliedby \textit{let's first distribute the exponent}
\\\\\\
(9^{-3}c^{-9\cdot -3})\implies 9^{-3}c^{27}\implies \cfrac{1}{9^3}\cdot c^{27}\implies \cfrac{c^{27}}{729}[/tex]