[tex]\left( - \dfrac{3n}{18n^2}\right)^{-18} \times(-6n)^{-15}\\\\\\= \left(-\dfrac{1}{6n} \right)^{-18} \times \dfrac{1}{(-6n)^{15}}\\\\\\=\left[(-6n)^{-1}\right]^{-18} \times \dfrac 1{(-6n)^{15}}\\\\\\=(-6n)^{18} \times \dfrac 1{(-6n)^{15}}\\\\=(-6n)^{18-15} \\\\=(-6n)^3\\\\=-216n^3[/tex]
