Answer: last option.
Explanation:
The negative exponent rules establishes the following:
![a^(-n)=(1)/(a^n)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2akbux28prddhditwp0q4aiy3r8t2enywp.png)
The power to power property establishes:
![(a^b)^c=a^(bc)](https://img.qammunity.org/2020/formulas/mathematics/high-school/8l0dpzguk924bwhcrjrz9djm4oq8apr76o.png)
The product of powers property establishes that when you multiply two powers with equal base you must add the exponents.
Applying the properties, you obtain the equivalent expression shown below:
![((1)/(x^2*x^6))^3=((1)/(x^8))^3=(1)/(x^(24))](https://img.qammunity.org/2020/formulas/mathematics/high-school/3qk5pyhbq4nn0k8mj3fzrbkjhkr4ujj4t7.png)
Therefore the answer is the last option.