X$^-$ is the stronger base.
Work Step by Step
The conjugate base of a weak acid is a weak base. The conjugate base of a strong acid has negligible basicity. Since HX is the weaker acid, X$^-$ will be the stronger base.
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.