Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2wz/ Esercizi: http://www.khanacademy.org/exercises?exid=writing_expressions_1 Traduzione in Italiano del video Equations 2 http://www.youtube.com/watch?v=XoEn1LfVoTo http://www.khanacademy.org/video/equations-2?playlist=Algebra Help us caption & translate this video! http://amara.org/v/B2wz/