if someone can do your course work for you!
A few questions:
Do you know what Gauss-Jordan Elimination is?
Do you know how to apply it to matrices?
Can you program in C++?
If any of the answers are no, then I'm afraid you may need to do a little more bookwork my friend.
Alternatively, here's a tip, use Google.
I googled it and got to a wikipedia link: http://en.wikipedia.org/wiki/Gauss-Jordan_elimination and at the bottom of that page there are external links. These link to the program you're after, but written in Matlab, Python and Basic.
Maybe you can use these programs as a reference for the logic and algorithm to write yours in C++.
Good luck with the coding, and good luck in your course.