Testing out latex on markdown#

When $a \ne 0$, there are two solutions to $ax^2 + bx + c = 0$ and they are: $$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$ To align equations, $$\begin{align} x &= x \\ x &= y \\ x &= z \end{align}$$