搜题请搜索小程序“爱下问搜题”
问题 解答题

用因式分解法解下列方程：

（1）（x+2）2=3x+6；

（2）（3x+2）2-4x2=0；

（3）5（2x-1）=（1-2x）（x+3）；

（4）2（x-3）2+（3x-x2）=0．

答案

（1）原方程可变形为

（x+2）（x+2-3）=0，

（x+2）（x-1）=0．

x+2=0或x-1=0．

∴x1=-2，x2=1．

（2）原方程可变形为

（3x+2-2x）（3x+2+2x）=0，

即（x+2）（5x+2）=0．

x+2=0或5x+2=0．

∴x1=-2，x2=-

2
5
．

（3）原方程可变形为

（2x-1）（5+x+3）=0，

即（2x-1）（x+8）=0

2x-1=0或x+5=0

∴x1=

1
2
，x2=-8．

（4）原方程可变形为

2（x-3）2-x（x-3）=0，

（x-3）（2x-6-x）=0，

（x-3）（x-6）=0．

x-3=0或x-6=0．

∴x1=3，x2=6．

阅读理解

读短文，判断正(T)误(F)。

Dear mother,

     How are you? I'm fine.

     Today is Sunday. I don't go to school. I stay at home. I am writing to you now. Every day I go to

school at seven thirty in the morning. We have four classes in the morning. We read and write Chinese at

school. There are forty-five students in my class. Four of them are from the U. S. and five from Australia.

The other students are Chinese. Now I have many Chinese friends. My classmates are all my friends. They

teach me Chinese and I teach them English. I can speak a little Chinese now. Please don't worry about me.

                                                                                                                                    Yours,

                                                                                                                                         Jenny

(     ) 1. Jenny's mother writes the letter.

( ) 2. Every day Jenny has four classes.

( ) 3. Jenny can speak Chinese well.

( ) 4. There are forty-five students in Jenny's class.

( ) 5. Four of Jenny's classmates are from Australia.
查看答案
单项选择题 A1/A2型题

下列哪项属于教育诊断中的倾向因素（）

A.实现或形成某行为所必需的技能、资源和社会条件

B.价值观

C.同伴的影响和领导

D.亲属以及保健人员的劝告

E.社会的支持
查看答案