Watch this youtube video first: http://www.youtube.com/watch?v=l6_ghhd7kwQ Then go to these sites to see step by step examples: http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=131529 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=148086 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=90856 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=631640 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=512996 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=164148 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=148086 http://www.algebra.com/cgi-bin/jump-to-question.mpl?question=427654 Edwin