Answer:
1/ 27
Step-by-step explanation:
[tex] = 81^{ \frac{-3}{4} } [/tex]
[tex] = (\frac{1}{81}) ^{ \frac{3}{4} } [/tex]
[tex] = (\frac{1}{3}) ^3 [/tex]
[tex] = \frac{1}{27} [/tex]