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【329889】9.2 二次根式的加法与减法

时间:2025-02-07 09:22:46 作者: 字数:1804字


9.2 二次根式的加法与减法

一、填空题:

1.计算: <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ______

2.写出两个与 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是同类二次根式的根式:______

3.若最简二次根式 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是同类二次根式,则x______

4.若最简二次根式 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是同类二次根式,则a______b______

5.计算: <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ______

6.三角形的三边长分别为 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> ,这个三角形的周长是______cm

二、选择题:

7.计算 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的结果是( )

(A)3 (B) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

8.下列二次根式中,属于最简二次根式的是( )

(A) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (B) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

9.下列二次根式中,与 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 是同类二次根式的是( )

(A) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (B) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

10.在下列各组根式中,是同类二次根式的是( )

(A) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (B) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>  <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

11.下列各式的计算中,成立的是( )

(A) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (B) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

12.若 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 的值为( )

(A)2 (B)2 (C) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (D) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

三、解答题:

13.计算:

(1) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (2) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (3) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>



(4) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (5) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>




(6) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (7) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>






(8) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (9) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>







(10) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (11) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>






四、问题探究

教师节到了,为了表示对老师的敬意,小明做了两张大小不同的正方形壁画送给老师,其中一个面积为800cm2,另一个面积为450cm2.他想如果再用金彩带把壁画的边镶上会更漂亮,他现在有1.2米金彩带,请你帮忙算一算,他的金彩带够用吗?如果不够用,还需买多长的金彩带?( <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 1.414,保留整数)



参考答案

1 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 2.略 32 4 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 5 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> 6 <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

7B 8D 9D 10B 11D 12A 13(1) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (2) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (3) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(4) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (5) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (6) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (7)24 (8) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

(9) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a> (10)1 (11) <a href="/tags/43/" title="加法" class="c1" target="_blank">加法</a> <a href="/tags/52/" title="减法" class="c1" target="_blank">减法</a> <a href="/tags/896/" title="根式" class="c1" target="_blank">根式</a>

问题探究:不够用,还需买78cm