Here's a simple equation: [E = mc^2]
And here's a more complex equation: [ \int_{-\infty}^{\infty} e^{-x^2} dx = \sqrt{\pi} ]
Some inline equation like [a^2 + b^2 = c^2] in the middle of text.
Here's a matrix: [ \begin{bmatrix} 1 & 2 & 3 \ 4 & 5 & 6 \ 7 & 8 & 9 \end{bmatrix} ]