博客园已经内置添加了MathJax以支持LaTeX数学公式
For inline formulas, enclose the formula in $...$.
$a=b+c$
For displayed formulas, use $$...$$
$$a =b +c$$
References
https://www.cnblogs.com/cmt/p/3279312.html
https://math.meta.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference