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146.14746-!-item-!-187;#058&010097
If the symbol △ represents either addition or multiplication, which operation does it represent?
(1)a △ b = b △ a for all numbers a and b.
(2)a △ ( b – c ) = ( a △ b )– ( a △ c )for all numbers a, b, and c.
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这道题的答案是b 而不是a 我很疑惑,a可以满足加法和乘法,而b只能满足乘法不能满足加法。 |
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