Mathtest

[math]\displaystyle{ \frac{n!}{k!(n-k)!} = {n \choose k} }[/math]

[math]\displaystyle{ x = a_0 + \cfrac{1}{a_1 + \cfrac{1}{a_2 + \cfrac{1}{a_3 + \cfrac{1}{a_4} } } } }[/math]