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1、Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.1、什么叫方程？方程必须具备哪些条、什么叫方程？方程必须具备哪些条件？件？2、判断哪些是方程？、判断哪些是方程？X+30=455a3b6b=150-65c30=455m+40=1607k+645 未知数未知数等式等式值相等值相等Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5
2、.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.200100200 = 1002100Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.200 = 1002 200100 100+100+100Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-20
3、11 Aspose Pty Ltd.200100200 +200 = 1002 +200100Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.200100200 +a = 1002 +a100aaEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Lt
4、d.你们发现了什么？你们发现了什么？Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.两边都拿掉两边都拿掉1个花瓶，天平还平衡吗？个花瓶，天平还平衡吗？左边左边a右边右边 aaEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd. 等式两边同时加上
5、（或减等式两边同时加上（或减去）去）相同的数相同的数，左右两边仍，左右两边仍然相等。然相等。等式的性质：等式的性质：Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.练习：判断式子是否成立。练习：判断式子是否成立。 x218 x2 + 218 （ ） x2 +218 2 （ ） x2218 +3 （ ） x22182 （ ） x2 +218 +2 （ ）Evaluation only.Created with Aspo
6、se.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.空杯子重100g,水重x克。平衡100g100g100g50g100g100g50gEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.空杯子重100g,水重x克。平衡100g100+x250100g100g50gX=？Evaluation only.Creat
7、ed with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.100+x250x150使方程左右两边（ ）的未知数的（ ），叫做方程的解。x=150是方程100+x=250的（ ）。求方程的解的过程过程叫做解方程。解解相等相等值值Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.下列括号中，哪个是
8、方程的解？下列括号中，哪个是方程的解？3x=12 (x=4 x=6 )3.5- x=2.1 (x=3.8 x=1.4 )0.7(x-2)=5.6 (x=8 x=10 )(x+0.4)2.5=1 (x=2 x=2.1 )Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.X个个9个x+3=9Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Prof
9、ile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.x方程两边同时减去同一个数，左右两边仍然相等。x + 3 = 9 x=- 3- 36为什么要减为什么要减3？Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.x=6是不是正确答案呢？你会验算吗？x+3=9 x=6方程左边=x+3所以，x=6是方程的解。检验检验：=6+3=9 =方程右边方程右边Evaluation only.C
10、reated with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.X + 39x6求方程的解的求方程的解的过程过程叫做叫做解方程解方程。使方程左右两边相等的使方程左右两边相等的未知数的值未知数的值，叫做，叫做方程的解方程的解。像上面，像上面，x=6就是方程就是方程x+3=9的解。的解。X+3393解：解：Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copy
11、right 2004-2011 Aspose Pty Ltd.左边墨水的数量扩大到原来的左边墨水的数量扩大到原来的2 2倍，倍，右边铅笔盒的数量也扩大到原来的两倍，右边铅笔盒的数量也扩大到原来的两倍，天平还保持平衡吗？天平还保持平衡吗？如果天平两边物品的数量分别扩大到原来的如果天平两边物品的数量分别扩大到原来的3 3倍、倍、4 4倍、倍、5 5倍倍天平还保持平衡吗？天平还保持平衡吗？Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose P
12、ty Ltd.1 1个排球和几个皮球重量相等？个排球和几个皮球重量相等？=Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.等等式式两两边边同同时时乘乘或或除除以以相相同同的的数数（0 0除除外外），等等式不变。式不变。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 As
13、pose Pty Ltd.解方程：3x=18xxx表示什么？Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.解方程：3x=18方程两边同时除以一个不等于0的数，左右两边仍然相等。xxx3x（ ）=18（ ）33Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose
14、 Pty Ltd.解方程：3x = 183x3 = 183检验一下吧！解：解：X = 61X = 6Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.努努力力吧吧！Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.解方程：解方程：x + 3.2
15、 = 4.6x 1.8 = 4Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.X元元 X元元 X元元 X元元11.2元4x=11.2解：4X 4=11.2 4 X=2.8数学藏于生活中数学藏于生活中Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty L
16、td.共共128条条平均分在平均分在x个鱼缸里，每个鱼缸个鱼缸里，每个鱼缸8条条128X=8Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.今天上午8时，洪泽湖蒋坝水位达14.14m，超过警戒
17、水位0.64m。今日水位14.14m警戒水位警戒水位是多少米？14.14-0.64=13.5（m）水位高度超过警戒水位高度水位高度超过警戒水位高度=警戒水位警戒水位Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.今日水位14.14m警戒水位警戒水位+超出部分=今日水位今天上午今天上午8时，洪泽湖蒋坝水位达时，洪泽湖蒋坝水位达14.14m，超过警戒水位，超过警戒水位0.64m。警戒水位是多少米？警戒水位是多少米？解：设
18、警戒水位为解：设警戒水位为x米。米。x+0.64=14.140.640.64=14.140.64=13.5=13.5方程两边都减去同一个数方程两边都减去同一个数,方程两边仍然相等方程两边仍然相等.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.列方程解应用题的步骤是什么？列方程解应用题的步骤是什么？（1）弄清题意，找出未知数，弄清题意，找出未知数，设为设为x（2）找出应用题中的）找出应用题中的等量关系等量关系，列列方
19、程方程（3）解解方程方程（4）验算验算，写出答案，写出答案Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.小丽拿桶接了半个小时，共接了小丽拿桶接了半个小时，共接了1.8kg水。水。你知道一个滴水你知道一个滴水的水龙头每分钟的水龙头每分钟浪费多少水吗？浪费多少水吗？Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0
20、.Copyright 2004-2011 Aspose Pty Ltd.小丽拿桶接了半个小时，共接了小丽拿桶接了半个小时，共接了1.8kg水。水。每分钟滴的水每分钟滴的水30=半小时滴的水半小时滴的水你知道一个滴水你知道一个滴水的水龙头每分钟的水龙头每分钟浪费多少水吗？浪费多少水吗？解：设每分钟滴解：设每分钟滴x克水克水 1.8Kg=1800g30X=180030X30=180030X=60答：一个水龙头每分钟浪费答：一个水龙头每分钟浪费60克水。克水。Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile
21、5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.努努力力吧吧！Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.丽丽身高丽丽身高1.17米，她比米，她比去年长高了去年长高了6厘米，她厘米，她去年身高多少？去年身高多少？用算术法计算用算术法计算:1.17米米=117厘米厘米1176= 111（厘米）（厘米）答答:她去年身高她去年身高111厘米厘米.Evaluation only.Cr
22、eated with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.丽丽身高丽丽身高1.17米，她比米，她比去年长高了去年长高了6厘米，她厘米，她去年身高多少？去年身高多少？用方程解答用方程解答:解解:设她去年身高设她去年身高厘米厘米1.17米米=117厘米厘米6=11766=1176=111答答:她去年身高她去年身高111厘米厘米.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile
23、 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.根据题中的数量关系列出方程，并求出方程的解。根据题中的数量关系列出方程，并求出方程的解。解解:2.7=6.92.72.7=6.92.7=4.2Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.根据题中的数量关系列出方程，并求出方程的解。根据题中的数量关系列出方程，并求出方程的解。原价：原价：x元元优惠：优惠：45元元现价：现价：12
24、8元元解解:45=1284545=12845=173Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.根据题中的数量关系列出方程，并求出方程的解。根据题中的数量关系列出方程，并求出方程的解。每盒每盒18元元x元/枝解解:12=18=181212=1812=1.5=1.5Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0
25、.0.Copyright 2004-2011 Aspose Pty Ltd.根据题中的数量关系列出方程，并求出方程的解。根据题中的数量关系列出方程，并求出方程的解。每杯75g解解:4=7544=754=300Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.
