Use this code
![](http://www.forkosh.com/mathtex.cgi? \Large x=\frac{-b\pm\sqrt{b^2-4ac}}{2a})
![](http://www.forkosh.com/mathtex.cgi? \Large x=\frac{-b\pm\sqrt{b^2-4ac}}{2a})
Let's try another equation:
![](http://www.forkosh.com/mathtex.cgi? \Large \int_13x2dx)