2x-5=x-1

x+x=x-1+5

x+x=x+4

x=4

1.They have just decided (decide) to buy a new house.
2."Gone with the Wind" is the most interesting film we have seen ( see) recently.
3.Did you see (see) Nam last Sunday? Oh, no I haven't seen (not see) him for many days now.
4.Since when have you learnt (learn) E? I have learnt (learn) it since I was( be) a girl of twelve.
5. Have you ever been (be) to HCM city? -No, I haven't been (not be) there yet. But my parents have been (be) there twice this year.
6.They have done (do) nothing since they got (get) up.
7.My brother joined (join) the army when he was ( be) 18. He has served (serve) in the army for 3 years and then went (go) to universiy.

8.How long have you lived (live) in this town? -I have lived (live) in this town for ten years.
9.My sister finished (finish) school in 1997 and has been (be) a student at the National University since then.
10.My parents have gone (go) out.They will be back soon.

1. C. On

2. B. burned

3. C. began

4. A. of

5. B. put

6. A. teams

7. A. help

8. C. brought

9. B. care

10. B. received

Change the sentences into the active voice.

Our salary was going to be increased.

=> The boss was going to increase our salary.

The boys couldn't be found anywhere.

=> The boys parents couldn't find the boys anywhere.

Cấu trúc It is/ was not until... that... + S + V được dùng để nhấn mạnh khoảng thời gian hoặc thời điểm mà một sự việc xảy ra. Khoảng thời gian hoặc thời điểm có thể diễn tả bằng một từ, một cụm từ hoặc một mệnh đề.

Ví dụ:

She didn't get home until 11 p.m

=> It was not until 11 p.m that she got home. (Mãi đến 11 giờ cô ấy mới về nhà)

We didn't know the truth until the book was published.

=> It was not until the book was published that we knew the truth. (Mãi đến khi cuốn sách được xuất bản chúng tôi mới biết sự thật.)

Lưu ý: Cấu trúc "It is/was not until..." phải nối với mệnh đề theo sau bằng "that" không dùng "when".

Incorrect: It is not until 2000 when she got married.

Correct: It is not until 2000 that she got married.

3ⁿ⁺² - 2ⁿ⁺² +3ⁿ - 2ⁿ = 3ⁿ . 3² - 2ⁿ. 2² +3ⁿ -2ⁿ

                             = 3ⁿ(3²+1) - (2ⁿ.2² +2ⁿ)

                             =3ⁿ . 10 - 2ⁿ .5

                             =3ⁿ.10 - 2^n-1 .2 .5

                             = 3ⁿ.10 - 2^n-1 .10

                             = 10(3ⁿ - 2^n-1)

vì 10 chia hết cho 10 nên 10(3ⁿ-2^n-1) chia hết cho 10

                         =>  3ⁿ⁺² - 2ⁿ⁺² +3ⁿ -2ⁿ chia hết cho 10

It was explained that this powerful engine pulled the train.

(1) was

(2) live

(3) changed

(4) news

(5) so

(6) after

(7) children

(8) over

(9) play

(10) than

Dịch các câu sau sang tiếng anh.

1/ Chủ tich Hồ Chí Minh sinh vào ngày tháng năm nào? Ngày 19/5/1890.

=> -What is President Ho Chi Minh's date of birth?
- When were President Ho Chi Minh born?

2/ Khóa học này kéo dài trong bao lâu?

=>How long does this course last?

3/ Năm nhuận có bao nhiêu tháng?

=>How many months are there in a leap year?

4/ Mấy giờ thì lớp học của bạn bắt đầu?

=>What time does your class start?

5/ Môn học nào bạn yêu thích nhất?

=>Which subjects do you like best?

Chọn từ có phần gạch chân phát âm khác

1.A.math B.month C.with D.both

2.A.selection B.education C.collection D.suggestion

3.Achemistry B.orchestra C.ache D.chew