I have followed this tip on how to convert PowerPoint (.pptx) slides to SVG (Save as PDF in PowerPoint > Open in Inkscape > Minor edit and Save as SVG) and had great success except when the slide has math equations in it, the text becomes Chinese characters. Is there a way to solve this issue?
I made a test. I saved some text and equations in Visio with CutePDF printer.
Inkscape opens the PDF with an equation, but the result was different depending on the used PDF import mode. Inkscape offered Poppler/Cairo import and Internal import to select.
Internal import messed up equations totally, but ordinary texts seemed to be ok. Everything was a multilevel ultra-complex group. Extension > Arrange > Deep Ungroup opened the knot. Ordinary text blocks were readable and editable, but the equations had got font replacement. Most symbols were something else than in the original. It didn't help that I unchecked the offered font substitution.
Poppler-Cairo import was visually ok, but all texts and equations were paths. They were not editable as text. Again everything was a big bizarre group, but it was fixed with Deep Ungroup.
In theory one can take the equations and images separately from a Poppler -Cairo import and texts from Internal import. That's a lot of work if the document is long. Poppler-Cairo import can use the embedded fonts in PDF, but it makes all curves.
If you haven't embedded the needed font to the PDF there's no possiblity to make the equations right - at least if you operate in a machine which hasn't the needed font.
You can try If you can convert the equations to images before saving as PDF. Unfortunately I have quite old MS Office and I know the things have changed radically after it.