At present, Apple has not implemented PDF/UA support in any PDF export solution, nor direct export support for PDF/A archival, or PDF/X printing standards. One can open a PDF in Preview, export it to another PDF, and select PDF/A (2b) and Linear PDF (fast web) features.
If the current versions of MS Word can provide the equation and accessibility features required by your university, then you should use Word whose continued development is supported by a large revenue stream. As an aside, LibreOffice supports PDF export to PDF/UA, and PDF/A-3b with the current version (7.2).
The Pages equation editor is backed by blahtex, a C++ application that supports limited features of, and converts LaTeX equations, to embedded MathML objects.
Otherwise, what Barry has posted.