[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] ~\dotfill[/tex]
[tex]\bf \cfrac{4(3x^2y^4)^3}{(2x^3y^5)^4}\implies \cfrac{4(3^3x^{2\cdot 3}y^{4\cdot 3})}{(2^4x^{3\cdot 4}y^{5\cdot 4})}\implies \cfrac{4(27)x^6y^{12}}{16x^{12}y^{20}}\implies \cfrac{108x^6y^{12}}{16x^{12}y^{20}} \\\\\\ \cfrac{108}{16x^{12}x^{-6}y^{20}y^{-12}}\implies \cfrac{108}{16x^{12-6}y^{20-12}}\implies \cfrac{27}{4x^6 y^8}[/tex]
