How do I write math equations in my blog?

I have been trying to do this for a long time and none of the methods I have come across seem to work for me. The most common suugestion I have seen is to use MathJax which can be activated by using this script

    <script src=""></script> <script async="" id="MathJax-script" src=""></script> 

This still doesn’t seem to work for me or maybe I am just doing it the wrong way. I know how to use LATEX but i am not familiar with html.