Answer:
1/216
Step-by-step explanation:
[tex]\\ \tt\hookrightarrow 6^{-8}\times 6^5[/tex]
[tex]\\ \tt\hookrightarrow 6^{-8+5}[/tex]
[tex]\\ \tt\hookrightarrow 6^{-3}[/tex]
[tex]\\ \tt\hookrightarrow \dfrac{1}{6^3}[/tex]
[tex]\\ \tt\hookrightarrow \dfrac{1}{216}[/tex]