五年级数学上册第四单元简易方程复习.ppt
25页
简易方程复习人教版五年级数学上册Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.1.用字母表示数应该注意什么？2.什么叫做方程？等式与方程有 什么区别和联系？3.什么叫做方程的解和解方程？Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.用字母 表示数数量关系运算定律和性质计算公式Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.加法交换律：加法结合律：乘法交换律：乘法结合律：乘法分配律：a＋b = b＋a（ a＋b ） ＋c = a＋（b＋c）a×b = b×a（ a×b ） ×c = a×（b×c）（ a＋b ） ×c = a×c＋b×c）Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.含有未知数的等式，叫做方程。
使方程左右两边相等的未知数的值， 叫做方程的解求方程的解的过程，叫做解方程简易方程：等式不一定是方程，方程一定是等式 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.（2） 如果用a表示长方形的长 , b表示宽，那么这个长方形的面积 S = 这个长方形的周长 C = 2(a+b) ab这个正方形的周长：c =（1） 如果用a表示正方形的边长 , 那么 4a 这个正方形的面积：S =a21.做一做Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.a×3=( )2.省略乘号，写出下面各式。
4.5× =( ) a×7×b=( )a+3+a=( )× ×2=( )3×a＋2×b=( )(a＋b)×2=( )5×c×d=( )3a7ab 3+2a3a+2b5cd 2a+2b x xx2 2x 4.5xEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.3.连一连比 a 多 2的数比a 少 2 的数2个a相加的和2个a相乘的积a 的 2 倍 a2 2a a+2 a-2 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.(1) a与b的和的一半是( )。
2) 有三个连续自然数，如果中间一个是a ,那么另外两个分别是（ ）和( ) 3) 食堂买来 千克大米，吃了 千克，还 剩( )千克如果 =45, =28，上面 的式子的值是( )4)一辆客车每小时行驶50km，行驶 小 时，共行驶了150km，请用含有字母的式 子表示三个数量之间的关系（ ） (a+b)÷2a-1a+14.填空17yxyxx-y50 =150xxEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.5.判断1）a×b×8可以简写成ab82） +5=4×5是方程3）方程一定是等式4） =2a（5）a÷b中，a、b可以是任何数。
×√××x√Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.(1)在 5+2x、 x÷4=1.8、 17+1.2=18.2 、 x+0.8 > 1、 3x-9=24÷X 中，方程有（ ）个 Ａ. 1 Ｂ. 2 Ｃ. 3 Ｄ. 4(2)方程3(X+2)=18的解是( ） Ａ.Ｘ=2 B.X=3 C.X=4 D.X=56.选择题BCEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.（3）每支铅笔a元，每本练习本b元。
小红买了5支铅笔 和3本练习本，一共应付（ ）元Ａ. 5a+3b Ｂ.3a+5b Ｃ.(a+b)×(5+3) （4）一本书有a页，小明每天看6页，看了x天，还没有 看完小明还剩下（ ）页 Ａ.6a-x Ｂ.6x-a Ｃ.a+6x Ｄ.a-6xADEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.7.解方程任选两题检验）10.2－5X=2.2 3×1.5+6X=33 0.5(x+2)=3 3x+1.5=13.5Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.思考：解方程的原理是什 么，需要注意哪些问题？Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.2.根据题意列方程 。
2) 从40 里减去一个数的3倍差是13，这个数 是多少？(1) 的6倍与31的和是49x 6 +31=49x解：设这个数是 x 40-3 =13x (3) 东方小学绿化校园五年级同学栽3行杨树， 每行 棵，又栽了15棵柳树，一共栽树39棵3 +15 =39xEvaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Cop。
