明明到邮局买0.8元与2元的邮票共13枚，共花去20元钱，问明明两种邮票各买了多少枚？_刷题宝

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明明到邮局买0.8元与2元的邮票共13枚，共花去20元钱，问明明两种邮票各买了多少枚？

上一题下一题 0.0难度选择题更新时间:2016-08-08 01:17:51

答案(点此获取答案解析）

解：设0.8元的邮票买了x枚，2元的邮票买了y枚，

根据题意得 ${\begin{matrix} x + y = 13 \\ 0.8 x + \end{matrix}$

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