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Joanna bought only $0.15 stamps and $0.29 stamps. How many $0.15 stamps did she buy?
(1)   She bought $4.40 worth of stamps.
(2) She bought an equal number of $0.15 stamps and $0.29 stamps.
答案:A
问题:为什么不选D呢?条件(2)的话设两种邮票各买了x个,则有:0.15x+0.29x=4.4,解得x=10啊。 查看答疑
问题:老师 为什么c不成立 还是没有听懂 为什么a单独就可以解出来 查看答疑
问题:C不行么? 查看答疑

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