Law of Exponent

Compare the terms.

Therefore, a = -2 and n = 3. From the law of exponent above, we receive:

Exponent Def. (For cubic)

Factor (-2)^3 out.

(-2) • (-2) = 4 | Negative × Negative = Positive.

4 • (-2) = -8 | Negative Multiply Positive = Negative.

If either denominator or numerator is in negative, it is the best to write in the middle or between numerator and denominators.
Hence,

The answer is - 1 / 8