commit cb890ae43bacd2be24bc74fad2e2e5cce8910995 added OOXML Math export in PPTX files.
unfortunately OOXML Math markup in PPTX isn't actually specified in ECMA-376 3rd ed., and can only be read by PPT 2010, not by PPT 2007.
so we use MCE (Markup Compatibility and Extensibility) to write the Math markup as an "extension" and a fallback.
currently the fallback is empty, but we could write a bitmap image shape instead, which could then be imported by PPT 2007 and older LibreOffice versions.
the implementation is in ShapeExport::WriteMathShape() in oox/source/export/shapes.cxx, see the "TODO: export bitmap shape as fallback"
functions to export bitmap shapes already exist in ShapeExport, and the model of the Math embedded object can be used to retrieve a preview image.
JanI is default CC for Easy Hacks (Add Jan; remove LibreOffice Dev List from CC)
I would like to work on this task. I could not understand the part relating to math embedded object.I would request you to provide some guidance.