Answer: 2/ a^12
Explanation:
(2a^4)^-3
Since this is a Power of a Power Rule, you multiply the exponents:
The rule:

(4)(-3) = -12
From this, you get this expression: 2a^-12.
However, since the exponent is also negative, you can inverse the number:
---> or ---> 2 / a^12
Both answers, 2a^-12 and 2 / a^12 can work, it is just a matter of how much you want to simplify the expression.