问题
填空题
如果2是一元二次方程x2+bx+2=0的一个根，那么常数b的值为______．
答案
把2代入方程有：
4+2b+2=0
2b=-6
b=-3．
故答案是：-3．
搜题请搜索小程序“爱下问搜题”
如果2是一元二次方程x2+bx+2=0的一个根，那么常数b的值为______．
把2代入方程有：
4+2b+2=0
2b=-6
b=-3．
故答案是：-3．
| 阅读理解。 | ||||||||||||||||||||||||||||||||||||
| I started school when I was five. I started this school when I was eleven and I will leave next year when I am sixteen. So I will spend 5 years at this school. The school year starts in September and ends in July. I have a two-week holiday in December, two weeks in April and six weeks in July and August. I also have a one-week holiday in February. In June next year, before I leave this school, I will take exams in 10 subjects. The exams are called GCSE. All children in England have to study English, math, science and a foreign language. They can also choose some other subjects. Here is my timetable for this year. School ends at 3:15 p.m.
| ||||||||||||||||||||||||||||||||||||
| 1. How old is the writer this year? | ||||||||||||||||||||||||||||||||||||
| A. Seventeen. B. Sixteen. C. Fifteen. D. Fourteen. | ||||||||||||||||||||||||||||||||||||
| 2. How many weeks of holiday does the writer have in a year? | ||||||||||||||||||||||||||||||||||||
| A. 6 weeks. B. 11 weeks. C. 10 weeks. D. 2 weeks. | ||||||||||||||||||||||||||||||||||||
| 3. What class does he begin to have at 9:20 on Wednesday? | ||||||||||||||||||||||||||||||||||||
| A. French. B. Math. C. History. D. Science. | ||||||||||||||||||||||||||||||||||||
| 4. When does the writer have math on Thursday? | ||||||||||||||||||||||||||||||||||||
| A. 10:35. B. 9:20. C. 12:50. D. 1:50. | ||||||||||||||||||||||||||||||||||||
| 5. Which statement is NOT TRUE according to the article? | ||||||||||||||||||||||||||||||||||||
| A. The writer usually has four classes in a day. B. Classes usually begin at 9:20 a.m. C. On Tuesday the writer begins to have geography at 12:50. D. The students at this school usually have lunch at 11:50. |