搜题请搜索小程序“爱下问搜题”
问题 解答题
解下列方程：
（1）2x2-
2
x-5=0
（2）3(
1
2
-x)2-6(x-
1
2
)-2=0．
答案

（1）这里a=2，b=-

2
，c=-5，

∵△=2+40=42，

∴x=

2
±
42
4
，

则x1=

2
+
42
4
，x2=
2
-
42
4
；

（2）设y=x-

1
2
，方程化为3y2-6y-2=0，

这里a=3，b=-6，c=-2，

∵△=36+24=60，

∴y=

6±2
15
6
=
3±
15
3
，

即y1=1+

15
3
，y2=1-
15
3
，

则x1=

3
2
+
15
3
，x2=
3
2
-
15
3
．

单项选择题

踢球质量的好坏由多方面的因素决定，而影响踢球力量的主要因素是（）。

A、助跑速度和随前动作

B、踢球腿的摆动速度

C、踢球腿的摆幅和摆速
查看答案
填空题
根据句意，选择适当的词并用其恰当的形式填空，每空只填一个词。

disappointed 　　  　offer 　  　　value 　  　　optimistic　　  　 relation 　　　　
responsibility 　  　imagine   　　suggest 　  　narrow 　　　  　　crime
1. Chinese people traditionally use different fruits as _____ to pray to God. 　　
2. To his _____, his father refused to give permission to attend the party. 　　
3. The report attempts to _____ the rise in crime to an increase in unemployment. 　　
4. We'll be _____ for the charges including any customs duties on export, as well as any
    service charges on exporting goods. 　　
5. Nothing is more _____ than the knowledge you have gained. 　　
6. He pointed a(an) _____ gun at me and pretended to shoot. 　　
7. The police have described the man as a violent and dangerous _____. 　　
8. _____ still believe we can solve the problem without going to war. 　　
9. We welcome any comments and _____ on this plan. 　　
10. Because we braked in time, we _____ missed hitting the other car.
查看答案