Both Microsoft Word and Microsoft
PowerPoint have a built-in equation editor to show equations. An equation
editor is an easy to use tool that facilitates the user to add mathematical
formulae in their PowerPoint. You can visit the given link and learn more about
it
https://support.office.com/en-us/article/write-an-equation-or-formula-1d01cabc-ceb1-458d-bc70-7f9737722702
Another option is to
use a blank A4 paper, write equations on it and then scan its image and import
it in your word or PowerPoint file.