You can put this solution on YOUR website! Sorry, I can't solve this, but the creator of this website Mr. Ichudov has created a lesson that I have read. Hopefully it will give you some understanding. The link is below.
http://www.algebra.com/algebra/homework/Matrices-and-determiminant/Wikibook-HSE-Matrices-6031.lesson
(Cut and paste to your Address)
Hope that helps you.