Answer:
4 and -4
Explanation:
This is because:
1. When fractions are raised to a negative exponent, the number will become a whole number, therefore, 1/4 and -1/4 does not work.
2. -8 does not work because when you square 8 it is 64 and not 16.
3. And finally, that leaves us with two options which 4 and -4 which both work because 4^-2 = 1/16 and -4^-2 = 1/16.
Therefore, the answer is 4 and -4.
Hope this helps! :D