观察下列各式:
;
;
;…,
(1)猜想它的规律,用含
的代数式表示出来.
(2)用你得到的规律,计算:
,并求出当
时代数式的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5637c341156cbfddfa28f6071eda1f1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b61dfa259a7cfab28fe63ff7d6211b1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a7f4890678dc22224b4d23a8c38fbf11.png)
(1)猜想它的规律,用含
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(2)用你得到的规律,计算:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03d4870582c042929dde05d2ab6920e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1bbd0f138a2fc993751d5f3a625039a.png)
20-21七年级·全国·假期作业 查看更多[1]
(已下线)练习4 代数式的有关概念-2020-2021学年【补习教材·寒假作业】七年级数学(湘教版
更新时间:2021-01-08 20:36:56
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相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】把几个数用大括号括起来,相邻两个数之间用逗号隔开,如:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1d2f98caea906d26aee92ea178551a.png)
,我们称之为集合,其中每一个数称为该集合的元素,集合的元素互不相同.如果一个所有元素均为有理数的集合满足:当有理数x是集合的一个元素时,2017-x也必是这个集合的元素,这样的集合我们又称为黄金集合.例如,
就是一个黄金集合.
(1)集合
______黄金集合,集合
______黄金集合;(填“是”或“不是”)
(2)若一个黄金集合中所有元素之和为整数M,且16133<M<16137,则该黄金集合中共有多少个元素?请说明你的理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed1d2f98caea906d26aee92ea178551a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51a010d3ab89608801503e61a5ae0485.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53990d2d1c080779b685613fb103ec58.png)
(1)集合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4adedf45d6231c2e146aa15f121edc3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e58c8c398ed7142bb3a38597c4142c5e.png)
(2)若一个黄金集合中所有元素之和为整数M,且16133<M<16137,则该黄金集合中共有多少个元素?请说明你的理由.
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解答题-计算题
|
适中
(0.65)
【推荐2】对任意一个三位数
,如果
满足各个数位上的数字互不相同,且都不为零,那么称这个数为“互异数”,将一个“互异数”任意两个数位上的数字对调后可以得到三个不同的新三位数,把这三个新三位数的和与111的商记为
.例如
=123,对调百位与十位上的数字得到213,对调百位与个位上的数字得到321,对调十位与个位上的数字得到132,这三个新三位数的和为213+321+132=666,666÷111=6,所以
=6.
(1)计算
和
的值,你发现了什么规律?请用自己的语言表达;
(2)若
=7,请直接写出
的最小值;
(3)若
,
都是“互异数”,其中
,
(1≤
≤9,1≤
≤9,
,
都是正整数),当
+
=16时,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae48677f8f6e1eaa980756a18378e593.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c45da0427641ec6399e370feb3140999.png)
(1)计算
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ca22abb7d46e5b6f2e2ce956820f37b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bb7230d04d5005143b35ea566fd8231b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae48677f8f6e1eaa980756a18378e593.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7b7168f4b9a9643a14fc0f7edc2604e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5997d973fca6739ad83d53d991fbaa35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a9305fe961d9201893cc97f826c1ead.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5d69e7fb25c60ee47440a1ece037544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abfc1f2e8eda0b91fb6ee21179d8c392.png)
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