解不等式
.
亮亮同学的解法如下:
解:去分母,得
. ①
移项,得
. ②
合并同类项,得
. ③
两边同除以
,得
. ④
找出亮亮同学解答中错误的步骤,并写出正确的解答过程.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee009a3c2fed43dc2f5aed9ba629558.png)
亮亮同学的解法如下:
解:去分母,得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8052d2ac9a79a852c2ec122a933e851.png)
移项,得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fbd1a3fd27d30b53b29aa0d5b9fc353b.png)
合并同类项,得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6c93a644cc85328e7fd30abaa8f4f27.png)
两边同除以
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbc6a613224461ade69362d46550474.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27f27cbb8185c1974d715ff95f8801c.png)
找出亮亮同学解答中错误的步骤,并写出正确的解答过程.
23-24八年级上·浙江金华·期末 查看更多[2]
浙江省金华市武义县2023-2024学年八年级上学期期末数学试题(已下线)第03讲 一元一次不等式(3个知识点+6类热点题型讲练+习题巩固)-【帮课堂】2023-2024学年七年级数学下册同步学与练(人教版)
更新时间:2024-02-28 16:05:10
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【知识点】 求一元一次不等式的解集解读
相似题推荐
解答题-问答题
|
适中
(0.65)
【推荐1】已知不等式5x+a<3的解集与-2x+5>1的解集相同,试求a的值.
您最近一年使用:0次
解答题-问答题
|
适中
(0.65)
【推荐2】阅读下列材料:
解答“已知
,试确定
的取值范围”有如下解法:
解:∵
,∴x=y+2,又∵
,∴
,即![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa65153e4042a7bcee802af1f637cd2c.png)
又
,∴
.…①
同理得:
.…②
由①+②得![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b98b4813601371551aa7c198985f1621.png)
∴
的取值范围是
.
请按照上述方法,完成下列问题 :
已知关于
的方程组
的解都是正数.
(1)求
的取值范围;
(2)已知
且
,求
的取值范围;
(3) 已知
(
是大于0的常数),且
的最大值.(用
含的式子表示)
解答“已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8883451eb5f6abdd9e39d63724596d51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
解:∵
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9021f0886cadf8d9f6f12d50be1d3d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67795f28a06de44afbfa1b7e023e755c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa65153e4042a7bcee802af1f637cd2c.png)
又
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a57458464618fcf619375a93d3c66d69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7a3a5db50910f6cba0243c52694c5694.png)
同理得:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a551a88ac426439803f564a3bbee04a.png)
由①+②得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b98b4813601371551aa7c198985f1621.png)
∴
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b88584cf1df43e28d03592c7998b1653.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9da0131e7c918b986def69145db6914f.png)
请按照上述方法,完成下列问题 :
已知关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2e647c14561826ba9e396acc5a3792c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0389c48218e1287bc06a8f009289f48b.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fc3a9b706714bcc1ba5fbebccc1a7f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7925a4d2592cb38bd92cd9d6b4e732b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20d6fc9b90f370fbb27552876b650f8f.png)
(3) 已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90f208c8c6cfc59871f2c78021f9e77f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87a5d0c6b73c9e34d24c116a5fd6b6fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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