remember
[tex](x^m)^n=x^{mn}[/tex]
and
[tex](ab)^c=(a^c)(b^c)[/tex]
and
[tex]x^{-m}= \frac{1}{x^m} [/tex]
so
[tex](6x^5)^{-3}=(6^{-3})((x^5)^{-3})=[/tex]
[tex]( \frac{1}{6^5} )(x^{-15})=( \frac{1}{7776} )( \frac{1}{x^{15}})=( \frac{1}{7776x^{15}})[/tex]
