1. In your blog default home page under "template" section select "Edit HTML" option. Add following line after <head> tag
<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> </script>
2. Now we can include math formulas as simple ASCII Math notation.
NOTE: We should use ∖( ...∖) for inline math and ∖[ ... ∖] for displayed math.
For inline math
To display \(\left(x-1\right)\left(x+3\right) \sqrt{a^2+b^2}\) as inline formula
Similarly for displayed math
\[\sqrt{a^2+b^2}x = a_0 + \frac{1}x = a_0 + \frac{1}{\displaystyle a_1 + \frac{1}{\displaystyle a_2 + \frac{1}{\displaystyle a_3 + a_4}}}{a_1 + \frac{1}{a_2 + \frac{1}{a_3 + a_4}}}\]
References:
1. Mathjax
2. Online Latex Editor