[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}}
\\\\
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\cfrac{a^{12}b^8}{a^2b^4}\implies a^{12}a^{-2}b^8b^{-4}\implies a^{12-2}b^{8-4}\implies a^{10}b^4[/tex]