[tex]\bf a^{-{ n}} \implies \cfrac{1}{a^{ n}}\qquad \qquad
\cfrac{1}{a^{ n}}\implies a^{-{ n}}
\\ \quad \\
% negative exponential denominator
a^{{ n}} \implies \cfrac{1}{a^{- n}}
\qquad \qquad
\cfrac{1}{a^{- n}}\implies \cfrac{1}{\frac{1}{a^{ n}}}\implies a^{{ n}} \\\\
-----------------------------\\\\
\cfrac{a^4b}{c^2d^3}\implies \cfrac{a^4}{1}\cdot \cfrac{b^1}{1}\cdot \cfrac{1}{c^2}\cdot \cfrac{1}{d^3}\implies a^4\cdot b^1\cdot c^{-2}\cdot d^{-3}\implies a^4bc^{-2}d^{-3}[/tex]
