Answer
$45x^{5}+108x^{3}$
Work Step by Step
$9x^{3}(5x^{2}+12)=(9x^{3})(5x^{2})+(9x^{3})(12)=45x^{3+2}+108x^{3}=45x^{5}+108x^{3}$
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.