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【330011】15.2.1分式的乘除(2)

时间:2025-02-07 09:17:32 作者: 字数:2491字

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

15.2.1 分式的乘除(2

学习目标

1、能应用分式的乘除法法则进行乘除混合运算。

2、能灵活应分式的乘除法法则进行分式的乘除混合运算。

3、在发展推理能力和有条理的表达能力的同时,体会学习数学的兴趣。

学习重点:掌握分式乘除法法则及其应用

学习难点:掌握分子分母是多项式的分式的乘除法混合运算

课前预习

阅读课本P12-13

1分式的约分:__________________________________________

最简分式:__________________________________________

下列各分式中,最简分式是( )

A <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> B <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> C <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> D <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

2、分解因式: <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

3、 计算 (1 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>2 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>



4、分数乘除法混合运算顺序是什么?

分式的乘除法混合运算与分数的乘除法混合运算类似

你能猜想出分式的乘除法混合运算顺序吗?

课内探究

1、计算(先把除法变乘法,把分子、分母分解因式约,然后从左往右依次计算)

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

注意:过程中,分子、分母一般保持分解因式的形







2、计算

1 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>2)(abb2÷ <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>



3、已知 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .求 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值



当堂检测

1、已知: <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ,则 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

2、计算 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的结果是( )

A <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>   B <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>   C <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>   D <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

3 计算

1 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>2 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>




4、先化简,再求值:

 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .其中 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>




课后训练

1、下列分式运算,结果正确的是( )

A. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> B. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> C. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>  <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> D. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

2、计算 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>  <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的结果是( )

A.x B. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> C. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> D. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

3 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> =_________________.

4、若m等于它的倒数,则分式 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值为_______________.

5、下列计算正确的是( )

A.a÷b· <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> =a B.a·b÷a·b=1 C. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ÷m·m÷ <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> =1 D.m3÷ <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ÷m3=1

6.化简 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ÷(yx)· <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的结果是( )

A. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> B. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> C. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> D. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

7.计算 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ÷(x+3)· <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的结果为( )

A. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> B. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> C. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> D. <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

8.已知ab≠0,且2a3b=0,则代数式 <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值是( )

A.12 B.0 C.4 D.4或-12

9.计算: <a href="/tags/153/" title="乘除" class="c1" target="_blank">乘除</a> <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .