[tex]\bf ~\hspace{7em}\textit{negative exponents} \\\\ a^{-n} \implies \cfrac{1}{a^n} ~\hspace{4.5em} a^n\implies \cfrac{1}{a^{-n}} ~\hspace{4.5em} \cfrac{a^n}{a^m}\implies a^na^{-m}\implies a^{n-m} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ (4x^{-4}y^2)^{-3}\implies \cfrac{1}{(4x^{-4}y^2)^3}\implies \stackrel{\textit{distributing the exponent}}{\cfrac{1}{\left( 4^3x^{-4\cdot 3}y^{2\cdot 3} \right)}} \\\\\\ \cfrac{1}{64x^{-12}y^6}\implies \cfrac{x^{12}}{64y^6}[/tex]