You can put this solution on YOUR website! When you see problems like this one, the first method to try is to see if the higher order polynomial has the lower order one as a factor.
and so it does
Here is a URL that helps with this type of factoring
Enjoy
http://72.3.253.76:8080/webMathematica3/quickmath/page.jsp?s1=algebra&s2=factor&s3=basic