Equações

Not a user of MathMl or general equations as a whole - no expert here just a few thoughts.

If you’re bringing equations from Word or Google Docs into InDesign, there isn’t a perfect native way to do it  but there are practical workflows, and a few traps to avoid.

What works

Convert to MathML (via MathType) + import with a plugin

Convert Word/Docs equations to MathML using MathType.

Bring them into InDesign using MathTools or InMath.

This keeps equations editable and properly aligned.

or

Export as vector graphics
If you don’t need to edit in InDesign, you can export each equation as:

SVG

PDF

EPS
…then place them normally.

MathType is the easiest way to convert Word equations into real vector artwork.

What to watch out for

SVG issues
InDesign supports SVG, but not all SVG math exports are clean. Some use embedded fonts or awkward groups that shift baselines or degrade transparency. Test before committing to SVG as your main workflow.

Plus SVG is rgb only, so you'd have edit them and save out as illustrator files. 

Low-res PNGs
Copy-and-paste or exporting directly from Google Docs will often give you PNG equations. These look fuzzy in print and don’t scale. Avoid unless the equation is tiny.

PDF limitations
PDF is vector, but:

Colours are often forced to RGB, which can cause problems in print workflows.

Some PDF equation exports flatten transparency or embed weird font subsets.

InDesign can’t edit them, only place them.

EPS is old
EPS works and is vector, but it doesn’t support modern transparency and is generally being phased out.

What doesn’t work well

Importing .docx directly nDesign rasterizes or drops equations

Copy/paste from Word or Docs almost always PNG

Docs PDF export equations often embed as low-res bitmaps

Best free-ish practical workflow

Word → MathType trial → Export equations as SVG or PDF → Place in InDesign.

Best professional workflow

MathTools plugin + MathML.

This is what publishers use for journals, textbooks, and STEM layout.