先化简,再求值:
,其中
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a9099a3ecc884b362c0e62a3e58d2c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74490a23cd584fd39cea93ca3ca07106.png)
更新时间:2023-07-10 10:18:54
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相似题推荐
解答题-计算题
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适中
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【推荐2】请你先将式子
÷(1+
)化简,然后从﹣1、0、1中选择一个数作为a的值代入其中再求值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51ce388246ea848474f6e0ae3c834a8b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28c1fc13eb0b3a5b7e9787a017efb7b8.png)
您最近一年使用:0次
解答题-问答题
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适中
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【推荐3】阅读材料:
小明的数学兴趣小组在深度学习过程中,对“完全平方数(式)”有了更深刻的全面了解.他们先回顾“有理数”,知道1,4,
,0.25,…,等这样的数,可以写成
,
,
,
,…他们称它们为完全平方数;然后回顾“整式的乘法与因式分解”这个章节,掌握了
,等这样的整式,可以写成
,
,
,…,他们称它们为完全平方式,他们发现这些数式的变形有时能给问题解决提供方便.现在,小明团队学习了“二次根式”后,能熟练把任意一个非负数改写成一个非负数的平方形式,如
,
,
,
,…,等,小明他们类比称这些非负数(式)为二次根式中的完全平方数(式).
下面,请跟随他们探究、解答下列问题:
(1)请分解因式:
________________.
(2)
.
反之,
,
.
(3)仿上例,化简:
.
(4)继续进行以下探索:
设
(其中a、b、m、n均为整数),则有:
.
∴
,
.
这样就找到了一种把类似
的式子化为完全平方式的方法.
方法迁移:当a、b、m、n均为正整数时,若
,用含m、n的式子分别表示a、b,得:
__________,
__________;
利用上述探索的结论,找一组正整数a、b、m、n,
使得
:
________,
________,
_________,
_________;
(5)若
,且a、m、n均为正整数,求a的值.
小明的数学兴趣小组在深度学习过程中,对“完全平方数(式)”有了更深刻的全面了解.他们先回顾“有理数”,知道1,4,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa1dc7b04bf9b86c558d6456855b3ca8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1db1c8f88c5de20586db0cde44d3e28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c298df12fdcbf7897dbfa93c4dbb8773.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/870d90c9bb8843a35042268d079002e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbe2ba91d179c2e967cfc13c622f7600.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0417ab1cc99ec9da69ef718d6f598c8d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e200e361ef8325b749723ccd10ee5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f170c352aedf4c39995383270c753e5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bd7f8e1006a48eba9ebbafb5b228210.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ec92ffe389dd1c02d940127430efe7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cc1387eb22827a11aa4feeaa2446238.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a850f020351705f137ca6becf347c22b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/290369baf6851a65ac47ddeb62cdca6e.png)
下面,请跟随他们探究、解答下列问题:
(1)请分解因式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/799392161a2127c6ea8a2389181dd3fe.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a3f027d9b7902bc24eb938a47a2210.png)
反之,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b8aa03e876384d8787ff818287a7cdc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e0c220f50992b3dc4190cb3ca2f5e7c.png)
(3)仿上例,化简:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb3095711cd322936f0cb8c9d990a0e6.png)
(4)继续进行以下探索:
设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30bc87004438cb6ea8a5e2d9ce5ad9b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67150712d7d3b944fa94c457d02e0d5d.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efab18eaf5760012863f7e45d2f7c563.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c470388373f20bebd306191029f5643.png)
这样就找到了一种把类似
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edb18960b2058db313c129b47af60af2.png)
方法迁移:当a、b、m、n均为正整数时,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9de2ca6dfe37acd999a7f6f02f2c9d20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
利用上述探索的结论,找一组正整数a、b、m、n,
使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9de2ca6dfe37acd999a7f6f02f2c9d20.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ccd4162c7d09f970cb77cadacdbe521.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6c57bbef89a37f1a3808c0ceeac0c22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f3cb8d72bb2e281b943b3b430138ef7.png)
(5)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51f68ef4dd6904d62c9e43d9515d363b.png)
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