1 . 我国古代数学著作《算数书》中有这样一个问题:“精米二斗值三钱,糙米三斗值二钱.现在有精、糙米共十斗,卖了十钱,问精、糙米各多少斗?”设精米、糙米斗数分别为x,y,则
,可解得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
________ ;![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070d1ea22a92808dad7489438c239629.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8345f5aaa18c18876a2159793ded5df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070d1ea22a92808dad7489438c239629.png)
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2 . 方程组
的系数矩阵为_________ ;增广矩阵为_________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28ffdd55593b0e3727caa9d9f189b52f.png)
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3 . 已知
,那么![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
______ ,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070d1ea22a92808dad7489438c239629.png)
______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c1236c42fedcab767a234dd10c38af3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ec0618ae3a4fde6d6220010af229b9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/070d1ea22a92808dad7489438c239629.png)
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