Данное видео показывает, как найти неизвестный член пропорции. Это видео - русский перевод лекции "Find an Unknown in a Proportion 2" Академии Хана (https://www.khanacademy.org/math/algebra/rational-expressions/ratios_algebra/v/find-an-unknown-in-a-proportion-2) This video is a translation of a Khan Academy lecture available at https://www.khanacademy.org/math/algebra/rational-expressions/ratios_algebra/v/find-an-unknown-in-a-proportion-2 This video is a Russian dubbed version of Khan Academy "Find an Unknown in a Proportion 2".