[This year, Henry will save a certain amount of his income, and he will spend the rest. Next year, Henry will have no income, but for each dollar that he saves this year, he will have 1 r dollars available to spend. In terms of r, what fraction of his income should Henry save this year so that next] [1000k 1m] [đánh vần tiếng anh] [�ݩ] [giải m㣠bã ẩn ngã¢n hã] [dmc-fx01 説明書] [ngoại giao] [58] [吉悅] [修罗都市·校园篇·第二部]