这是行内公式：$x^2 + y^2 = z^2$
$$ \frac{a}{b} + \sqrt{c} = \sum_{i=1}^{n} i^2 $$
$$ \begin{bmatrix} 1 & 2 \\ 3 & 4 \end{bmatrix} $$
$$ \begin{aligned} a + b &= c \\ d + e &= f \end{aligned} $$
这是行内公式：$x^2 + y^2 = z^2$
$$ \frac{a}{b} + \sqrt{c} = \sum_{i=1}^{n} i^2 $$
$$ \begin{bmatrix} 1 & 2 \\ 3 & 4 \end{bmatrix} $$
$$ \begin{aligned} a + b &= c \\ d + e &= f \end{aligned} $$
