posting with correct math formatting

[-GC-Phoenix]

ok so there are a lot of guys that seem able to post math equation that are formatted correctly for math, I was wondering how you guys do it.
And it ifs from a program, then what is the program, and where can I get it.

 

[pka]

At the very top of this webpage is a pull-down tab labeled Forum Help.
There are several links that will answer your question.
The best way is to use LaTeX.