I am involved in this project (XProc/XSLT/XML based):
http://transpect.github.io/modules-docx2tex.html
I am not sure if it is worth the setup time for a single conversion.
If you want to do it frequently, it absolutely is.
Once you have the tex, you can generate images from those sources.
If you really only want equations, then take a look at these single transpect modules:
mathtype2mml: https://github.com/transpect/mathtype-extension/
mml2tex: https://github.com/transpect/mml2tex