Recall that, if a and b are real numbers different from zero, and m and n are integers then:
[tex]\begin{gathered} (a^{}b)^m=a^mb^m, \\ (a^n)^m=a^{nm}, \\ a^{-m}=\frac{1}{a^m}. \end{gathered}[/tex]Using the above properties of exponents we get that:
[tex](ab^3c^2)^{-6}=\frac{1}{(ab^3c^2)^6}=\frac{1}{a^6b^{18}c^{12}}\text{.}[/tex]Answer:
[tex]\frac{1}{a^6b^{18}c^{12}}\text{.}[/tex]