Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2wf/ Esercizi: http://www.khanacademy.org/exercises?exid=quadratic_equation Traduzione in Italiano del video Quadratic Equation part 2 http://www.youtube.com/watch?v=y19jYxzY8Y8 http://www.khanacademy.org/video/quadratic-equation-part-2?playlist=Algebra