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1、实际问题与一元一次不等式教学实际问题与一元一次不等式教学 不等式的性质1 不等式的两边加(或减)同一个数(或式子),不等号的方向不变.不等式的性质2 不等式的两边乘(或除以)同一个正数,不等号的方向不变.不等式的性质 3 不等式的两边乘(或 除以)同一个负数,不等号的方向改变 注意:必须把不等号的方向改变一、不等式的性质复习回顾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 Cl
2、ient Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.第1页/共11页二解一元一次二解一元一次 方程的基本步骤方程的基本步骤去分母去括号.移项.合并同类项.系数化为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.
3、0.Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.第2页/共11页例题讲解 例题1、解下列不等式,并在数轴上把它们的解集表示出来 3x-2(x-2)6+3;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
4、 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.第3页/共11页练练 习习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.第4页/共11页 例
5、题2:2002年北京空气质量良好(二级以上)的天数与全年天数比达55%,如果到2010年这样的比值要超过70%,那么2010年空气质量良好的天数要比2002年至少增加多少?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 Asp
6、ose Pty Ltd.第5页/共11页 例题3:在一次知识竞赛中,有10道抢答题,答对一题得10分,答错一题扣5分,不答得0分,小玲一道题没有答,成绩仍然不低于60分,她至少答对几道题?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-
7、2011 Aspose Pty Ltd.第6页/共11页 2、我班几个同学合影留念,每人交0.70元。已知一张彩色底片0.68元,扩印一张相片0.50元,每人分一张,在将收来的钱尽量用掉的前提下,这张相片上的同学最少有几人?练习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
8、 Ltd.Copyright 2004-2011 Aspose Pty Ltd.第7页/共11页小 结去分母去括号.移项.合并同类项.系数化为一:解一元一次不等式的基本步骤:二:利用一元一次不等式解实际问题要注意怎样设未知数。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
9、Ltd.Copyright 2004-2011 Aspose Pty Ltd.第8页/共11页课本P1341、2、5作业布置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.第9页/共11页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.第10页/共11页感谢您的观看。第11页/共11页
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