Tìm giá trị nhỏ nhất của biểu thức \(\frac{5x^2-4x+4}{x^2}\)

Tìm x,y,z biết rằng x²+y²+z²+3=2(x+y+z)

cho tam giác ABC vuông tại A.Gọi D là một điểm thuộc cạnh AC sao cho góc ABD=góc ACB

a/ chứng minh hai tam giác ABC và ADB đồng dạng

b/ biết AD=4cm,DC=5cm.Tính diện tích tam giác ABC

Tính diện tích xung quanh của một hình lăng trụ đứng ABC.A'B'C', biết đáy tam giác ABC cân tại C,AC=15cm,AB=12cm,đường cao CC'=30cm

Đổi: 8 giờ kém 15 phút = 7 giờ 45 phút

Thời gian xe máy đi quãng đường AB là:

7 giờ 45 phút - 5 giờ 25 phút = 2 giờ 20 phút

Thời gian xe máy đi quãng đường AB nếu không tính thời gian nghỉ là:

2 giờ 20 phút - 12 phút = 2 giờ 8 phút

Đổi: 2 giờ 8 phút = \(\frac{32}{15}\) giờ

Quãng đường AB dài số km là:

42 x \(\frac{32}{15}\) = 89,6 (km)

Đáp số: 89,6km

chuyển những câu sau sang câu gián tiếp

1/ Mai said "we are going to have an English speaking club"

2/ "I will come here tomorrow" Tim said

3/ She asked me "Do you know him?"

4/ My friend told me "I can repair the bike my self "

5/ My friend said "After Tet everything is expensive"

6/ "Is Phong Nha cave far from Ha Noi,Lan?". Peter asked

7/ The teacher said to Nam "You must study harder in English"

8/ "Do many tourists visit Ha Long Bay every year, Nga?" Mary asked

9/ Nam said "My sister likes cooking"

10/ My mother said "I want our house to look clean and nice at Tet"

viết các động từ vào dạng đúng của nó

1. The weather (be) ..... very bad yesterday

2. My mother always (get) .... up early

3. Tom (see) ..... his classmates at the party tomorrow

4. He (give) .... me the letter a few minutes ago

5. They (make) ..... a lot of furniture next month

6. Peter and Alice (learn) .... French for two years

7. You (finish) .......... your homework yet?

8. Please don't say anything while i (learn) ...... my lesson

9. Tomorrow i (put) ........ our presents on that table

10. My friend (never see) ..... that sight

11. My uncle (live) ....... in Ho Chi Minh city since last year

12. He always (stay) ...... in bed late on sunday morning

13. Peter and Daisy (be) .... born in 1978

14. My sister always (wash) ...... her hands before meals

15. Look! The dog (run) ...... after him

16. Smith and Bobby (read) ....... books at this moment

17. Tom (repair) ..... his bicycle last friday

18. Mary and I (not watch) .... TV last night

19. I (just buy) ..... a new shirt

20. My brother came in while Tom and I (play) .... chess

21. Mr.Pike (work) ... in this factory for ten years

22. Viet Nam, Thailand and Malaysia (be) .... tropical countries

23. Ho Chi Minh city (be) ... the largest city in Viet Nam

24. Where you (go) ... last night ?

- I (go) .. to the cinema

25. What you (do) ... every morning?

26. You ever (be) .... to Russia ?

27. We (not meet) .... him two days ago

28. Uncle Ho (die) ... in 1969

29. Mr.Johnson (stay) ... in London now

30. How she (go) .... to school every day?

- She (go) ... to school by bicycle

đọc đoạn văn sau và trả lời câu hỏi

Nowadays every high-school in Ho Chi Minh city has its own library. Nam's school library is not as big as other public libraries but it is well-equipped with a variety of books.On open shelves we can find such kinds of books as fiction, non-fiction,text books,newspapers and magazines.

On saturday mornings and during the break Nam and his friends often go to the library to read books and newspapers.Miss Lan ,the librarian, is always at her desk to show them how to use the library cards when they want to borrow some reference books from the library.The school library helps Nam and his friends a lot in their study.

câu hỏi

1/Is Nam's school library smaller or bigger than other public libraries ?

2/ When do Nam and his friends often go to the library ?

3/ Is the school library helpful?

viết lại câu cho cùng nghĩa

1/ Mary hasn't returned my book yet

my book

2/ Her house is bigger than mine

my house

3/ To find a job at my age is difficult

It's

4/ Mai is younger than Lan

Lan

5/ My parents sent me to school when i was six years old

i

6/ To get acquainted with the regulation in a new school is easy

It's

7/ A bicycle isn't so expensive as a motorbike

A motorbike

8/ The principle doesn't write this letter

This letter

9/ Smoking a lot is harmful

It's

10/ Mary making a birthday cake in the kitchen

A birthday cake

đưa ra dạng đúng của các tính từ và trạng từ trong ngoặc

1/ He is (young) ..... than i am

2/ she is (old) .... as my sister

3/ Mary is the (beautiful) .... girl in her class

4/ Which is (big) ....,France or Thailand ?

5/ Maths is (difficult) .... than history

6/ A Ford isn't (comfortable) as a Mercedes

7/ This is the (powerful) .... machine in the whole factory

8/ Your watch is (good) ..... than mine

9/ She walks (slowly) .... as Betty

10/ Nobody is (happy) ..... than Jane