Answer
$-x^9$
Work Step by Step
By raising each factor to the power and then multiplying the exponents, we have
$$(-x^3)^3=(-1)^3x^{3\times 3}=-x^9
.$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.