[解題] 高一 數學 數與座標系
1.年級：高一
2.科目：數學
3.章節：
1-2 有理數與實數
4.題目：
判斷下列敘述眞偽:若a+b為有理數,ab為無理數,則a-b必為無理數.
答案:偽
5.想法：
我想了好幾個例子(例如:a=1+根號2,b=-根號2)套進去都沒辦法推翻它,
想請問這裡是否有強者能找出例子推翻它?還是題目錯了呢?
非常謝謝!
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09/15 00:43, , 1F
09/15 00:43, 1F
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09/15 00:44, , 2F
09/15 00:44, 2F
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09/15 00:45, , 3F
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09/15 00:46, , 4F
09/15 00:46, 4F
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09/15 01:05, , 5F
09/15 01:05, 5F
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09/15 01:07, , 6F
09/15 01:07, 6F
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09/15 01:09, , 7F
09/15 01:09, 7F
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09/15 01:11, , 8F
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09/15 12:35, , 9F
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09/15 12:36, , 10F
09/15 12:36, 10F
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09/15 12:37, , 11F
09/15 12:37, 11F