http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm http://www.purplemath.com/modules/rtnldefs.htm Rational Expressions Lesson.