How to write Math equations in Blogger

I am long gone from blogger because I could not find the way to write math in Blogger. I have done some google and combine all the clues and finally it 's work. This Is how I accomplish...

 1. Go to your blog's template option. You will see this page look. Click "Edit HTML"

2. Press "Ctrl+f" for the word "</head>". Copy the script ...

<script type="text/javascript"     src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX- AMSMML_HTMLorMML"></script>  <script type="text/x-mathjax-config">    MathJax.Hub.Config({  jax: ["input/TeX","output/HTML-CSS"],  extensions: ["tex2jax.js"],  tex2jax: {   inlineMath: [ ['$','$'], ['\\(','\\)'] ],   processEscapes: true  }    });  

</script>

...before the line "</head>". Then Click "Save Template"

 before

  after

This is the setup for your blogger page to accept Tex. However, ordinary people usually don't know how to write Tex. If you don't

3. Download and install MathType Software (https://www.dessci.com/en/products/mathtype/) or any software that does the job. I did downloaded the trail version.

4. Go to your Microsoft Word (I hope you have one on your window PC). Your will see the new tab "MathType" appear. Click that tab.

5. Click "Inline" . A new window will popup

6. Take your time to use this window to write equation by clicking around. It's not difficult. After you finish your equation, just close the window. Your eqaution will appear on Word document.

7. Then press "Toggle TeX". The equation will turn into TeX. So you just copy TeX and past onto your bolg post. Note that you should change your post to HTML mode before publish it

8. That's it. You should now have your equation on your blog like this...

$\frac{2}{5}\sqrt{{{a}^{2}}+{{b}^{2}}}\frac{n!}{r!\left( n-r \right)!}$ 


<I acknowledge the information from this
https://www.youtube.com/watch?v=zuXeU3l042Y
and modify by using the script from Xinyu Wang  from the youtube's comment>