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【330006】15.1.2分式的基本性质(2)

时间:2025-02-07 09:17:09 作者: 字数:1948字

 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

15.1.2分式的基本性质(2

学习目标

1、进一步理解分式的基本性质,并能用其进行分式的约分。

2、了解最简分式的意义,并能把分式化成最简分式。

3、通过思考、探讨等活动,发展学生实践能力和合作意识。

学习重点:分式的约分。

学习难点:利用分式的基本性质把分式化成最简分式。

课前预习

1、分式的基本性质是: 用式子表示

2、分解因式:(1x2—y2 、(2x2+xy 、(39a2+6ab+b2 、(4x2+x-6

自主探究:p129的“思考”。

归纳:分式的约分定义:

公因式:所有相同因式的最 次幂的积

最简分式:

通过上面的约分,你能说出分式进行约分的关键是什么?

约分:

1 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 、 (2 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>



3 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>4 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>


课内探究

1 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 、 (2 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>



3 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 、 (4 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>




5 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>






当堂检测


1约分:

(1) 2ab2/20a2b (2) x2-2x/x2-4x+4




(3) x2-9/x2-6x+9 (4)4x2-8xy+4y2/2x2-2y2





课后训练

1、填空:

(1)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> =  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> (2)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> = <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

3)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> = <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> (4)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> = <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

2、约分:

1 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>2 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> (3 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>




3、不改变分式的值,使下列分式的分子和分母都不含“-”.

(1)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> (2)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

3)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> (4)  <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>





4、判断下列约分是否正确:

1 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> = <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ( ) (2 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> = <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ( ) (3 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> =0( )

5、不改变分式的值,使分子第一项系数为正,分式本身不带“-”.

1 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>2 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>



3 <a href="/tags/253/" title="基本" class="c1" target="_blank">基本</a> <a href="/tags/386/" title="性质" class="c1" target="_blank">性质</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>