<math-tex> demo (mixed)

TeX: $\frac a b$

MathML: $\sqrt{x}$

AsciiMath: `a^2 + b^2 = c^2`

<math-tex>: c = \sqrt{a^2+b^2}

<math-tex mode="display">:

\sum_{k=1}^n k = \frac{n(n+1)}{2}