The answer should be obtuse. I'm not sure why it is saying it's incorrect but none of the other answers make sense.
Since you’re multiplying n^-6 and n^3, you can add the exponents: -6+3 = -3
n^-6 * n^3 = n^-3
If you need to finish without having a negative exponent in your answer, then remember a negative exponent means that factor is on the wrong side of the fraction.
n^-3 = n^-3 / 1 = 1/n^3
when the factor moves to the other side of the fraction, the side of the exponent changes.
This is the "commutative property of addition." The order in which you add numbers together doesn't matter, and doesn't change your final results.
