Add the mathjax javascript library to the head or body of the html
<script async="" id="MathJax-script" src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js" type="text/javascript">
</script>
To declare math equation use identifier
\ (...\) for inline or
\ [...\] for display
Note: no space between \ ( and \ [
Example to write 1/2
in latex: frac{1}{2}
in mathjax html (e.q. blogspot): \ ( \ frac{1}{2}\)
Note: no space between characters above
result
\(\frac{1}{2}\)
If you copy paste from word application with math equation support, the code may become messy, e.q word equation will result in many additional custom html tag.