The error here is that there was no check for extraneous solutions.
Work Step by Step
The error here is that there was no check for extraneous solutions. After all, $n=-3$ is an extraneous solution.
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.