Work Step by Step
First, pull out the greatest common factor. Then use the formula $a^2-b^2=(a+b)(a-b)$ to factor. $28h^2-63$ $=7(4h^2-9)$ $=7(2h+3)(2h-3)$
You can help us out by revising, improving and updating this answer.Update this answer
After 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.