LibreOffice
https://www.libreoffice.org/ - the free office suite
Extensions
TexMaths
TexMaths - a LaTeX equation editor for LibreOffice.
- sudo apt-get install texlive
- sudo apt-get install dvipng
- http://dvisvgm.sourceforge.net/Downloads
- install the extension
Test LaTeX expression: (x+y)^n + \frac{x}{n}
LaTeX Math Commands: http://www.artofproblemsolving.com/Wiki/index.php/LaTeX:Commands#Math_Commands