Bai tap 2.2 ([2] sec 5.4)

klmnopq stu fvwbxfvfybfvyb{d|}g|vwy~bvbye~|v{by~bdb€  ‚ƒ„ hij bcbdefgbg V3W,#,"!  2L=2B2I>H2Ia 12L2 2H2J J2Ia H2< BBF`2DB_G=_I`2Ia 32L=_I` J`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