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【330008】15.1分式

时间:2025-02-07 09:17:18 作者: 字数:1767字

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

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

15.1分式

基础巩固

1.式子① <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ;② <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ;③ <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> ;④ <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 中,是分式的有(  )

A.①② B.③④

C.①③ D.①②③④

2.若分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 有意义,则x的取值范围是(  )

Ax≠3 Bx3

Cx3 Dx3

3.下列各式中,正确的是(  )

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

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

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

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

4.若分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值为0,则a的值为__________

5.约分:(1) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

(2) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .

6.通分:

(1) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>  <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

(2) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>  <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .

能力提升

7.下列各式中,取值可以为零的是(  )

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

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

8.使分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 无意义的x的取值是(  )

A0 B1

C.-1 D±1

9.不改变分式的值,使分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的各项系数化为整数,分子、分母应乘以(  )

A10 B9

C45 D90

10.不改变分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值,使分子、分母最高次项的系数为正数,正确的是(  )

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

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

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

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

11.当x=-2时,分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 无意义,当x4时,分式的值为0,求mn的值.

参考答案

  1. C 点拨: <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的分母中不含字母,所以 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 不是分式; <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的分母中虽然含有π,但是π是常数,所以 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 不是分式.

2A 点拨:由分式分母3x不为0得不等式3x≠0,解这个不等式得x≠3.故选择A.

3D

43 点拨:由分式的值为零的条件得 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 解得a3.

5.解:(1) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

(2) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> .

6.解:(1) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

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

(2) <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a>

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

7B 8D

9D 点拨:取分子、分母各分数系数分母的最小公倍数,即为所乘的数.故选D.

10D

11.解:当分母xm0,即x=-m时,分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 无意义,解得m2.

xn0,即xn时,分式 <a href="/tags/846/" title="分式" class="c1" target="_blank">分式</a> 的值为0,即n4,mn246.