Giải pt về dạng ax+b=0

b) 2x(x + 2)^2 - 8x^2 = 2(x - 2)( x^2 + 2x + 4)

d) (x - 2)^3 + (3x - 1)(3x + 1) = (x + 1)^3

Hai đội công nhân cùng làm một công việc trong 3h 36 phút thì xong . Hỏi nếu mỗi đội làm một mình thì mất bao nhiêu lâu mới xog công việc. Biết rằng thời gian đội 1 làm ít hơn thời gian đội 2 là 3h.

Hai người cùng làm chung 1 công việc hết 6h , Nếu làm riêng nỗi người làm nửa công việc thì tổng số giờ là 12h30 phút . Hỏi nếu mỗi người làm 1 mình cả công việc thì mất bao nhiêu giờ

1. I ... ( go) there once a long time ago and( not/be)..... back since

2. Those drivers ( drive) ..... for three hours when a heavy storm suddenly (break) ........

3. Mike ( want) ....... to sit down because he( stand)..... all day at work.

4. The motorcycle ( belong) ....... to George for years before Tina ( buy) .. it last week.

5. I ( not/think) ..... he (come )......

6. At this time tomorrow , Peter( sit) ...... for the graduation examination , so now he ( feel ) . very nervous although he ( learn) . .... hard for more than three years.

Hardly a day góe by without my calling to Peter

I...........

We did not understand that custom until Peter explained it to us.

It was not..........

1.These shoes still need repairing.\

These shoes haven't ........

2. How long is it since you last saw Mary?

When.....

3, I was silly to say that.

I wish......

4. I have never had a cake as good as this.

This is the best cake........

5. This ís the last time I will speak to you

I will not............

6. Both Mary and Peter prefer coffe to tea.

Neither Mary nor Peter.....

7. This is the first time I have ever been in London .

I have never,........

8, I have never visited this museum before,

This is first time............

9. He turned off the computer first, and then he left.

After he .................

10. Jane does not often see Mary.

Jane seldom........

11. Susan last visited her parents at the end of last May.

Susan has not.........

12. The last time i had a denatl appointment was sĩ months ago.

It has been ..........

13. They moved to London in 2009

They have.....

14. You drove so fast.

I wish.......

15. This pasta is a new experience for me .

It ís the first time......

16. This is his first visit to the US.

He is

17. How long has it been since you left your village?

When .........

18. My son has beenw working as an accountant for two years.

My son began............

19. How long have you worked on that program?

When .....

20. Tom has arranged to play badminton with me tomorrow.

Tom and I........

21. I happened to meet Peter on the way to work yesterday.

I unexpectedly......

22. Hardly a day góe by without my calling to Peter.

I ....

23. We did not understand that custom until Peter explained it to us.

It was not..........

tìm lõi sai và sửa

1.By the time we wil get to California thí evening, we will have bêen driving more than four hundred miles.

2.I am thinking that E is difficult to learn

3. Last week, the firmen sescue the old woman who was being trapped on the third floor òf the burning building.

4. It ís already 9:30 and i hás been waiting here for over an hour.

5. If John do not get here in the next five minutes, I am going to leave

6. There are many reasons why I am liking to wear a uniform to school.

7. How many languages are John speak?

8. When we got home last night, we found that somebody has broken into the flat.

9. Kim didn't want to come to the cinema with us because she had already sê the film .

10. At first I thought I had done the right , but soon I realised that I have made a serious mistake.

11. The man sitting next to me on the plane was very nervous. He hadn't fly before.

12. Last night, while I was doing my homwork, Annw called . She said she í calling me on her cell phone from hẻr biology classroom.

13. University lecturers say they will be watching to make sure their school get , and efectively use, the mony the Nigerian government has promising.

The Titanic ( cross) .... the Atlantic when it ( strike ) ..... an iceberg

Please turn off the stove . The water ( boil ) ..... for more than fifteen minutes.

Mary ( work ) ... on the essay for two hours now and she ( hope) ..... that she ( finish) ... it in one more hour.

The guard ( listen) ...... to his iPod, so he ( not / hear) ..... the fire alarm

when thư boss ( walk) .... into the office, his secretary ( type) .. the report , and the accountant ( talk) .... on the phone

3x^3y^2-6x^2y^3 + 9x^2y^2

5x^2y^3 -25x^3y^4 + 10x^3y^3\

CMR a. x^2 -x+1>0 với mọi x

b. x^2+2x+2>0 với mọi x

c -x^2+4x-5<0 với mọi x

Bài 2

â) Thực hiện phép tính ( 2x^3-5x^2+10x-4) : ( 2x-1)

b) Chứng minh rằng thương của phép chia trên luôn có giá trị dương với mọi giá trị của biến

x^3-2x^2+x

x^2-2x-15