test

When $a ne 0$, there are two solutions to (ax^2 + bx + c = 0) and they are
$$x = {-b pm sqrt{texttip{b^2-4ac}{descriminant}} over 2a}.$$

\begin{aligned} a&=b+c \\ d+e&=f \end{aligned}
\bar{y}

\begin{Bmatrix} a & b \\ c & d \end{Bmatrix}
\begin{cases} a &\text{if } b \\ c &\text{if } d \end{cases}
\cfrac{2}{1+\cfrac{2}{1+\cfrac{2}{1}}}