tìm cặp số x,y thỏa mãn

\(x^2+y^2+\dfrac{1}{x^2}+\dfrac{1}{y^2}=4\)

tìm cặp số x,y thỏa mãn

\(x^2+y^2+\dfrac{1}{x^2}+\dfrac{1}{y^2}=4\)

put the verbs into the correct tenses

They (be) like a dog that once (come) here with a sore paw I (bandage)it for him and while I (do) this he (look) at me with great lonely eyes. He (come) back next day and everyday until his paw( be) well I (find) out that his master (go) away and kindly old couple( look) after the dog.

Read the following passage and complete the task below.

''... Of course, you can live very cheaply if you know that you're doing. For example, if you go round to someone's house at about 7 o' clock , they'll always invite to stay for a meal. I haven't bought any food for a week now . And then there's transport. It's ages since I paid a taxi fare. Why bother, when there are people with cars who can give you a lift ? I used to by my own cigarettes, too - but then i realised that people always offer them around when they have one themselves, I last bought a packet of cigarettes about two years ago . And I haven't been to a launderette since last september, either ,,, It's just a matter of talking what's offered to you - and it doesn't do anybody any harm really, does it? ..... Oh, by the way, I couldn't just use your phone for a moment, could I ...."

Find the sentences that contain the same meaning in the passage.

1. I last bought some food over a week ago.

2. I last went to a launderette last september.

3. It's about two years since I last bought a packet of cigarettes.

4. i haven't paid a taxi fare for ages.

Can't you write them in any other way ?

Mình đang cần gấp !!!!

Rewrite each of the following sentences, beginning as shown so that thee meaning stays the same.

1, This is my second visit to London.

--> This is the second time ...........................

2, After I arrived here, I started to feel better.

---> Since I...............................

3. There is a definite improvement in your work.

---> Lately your work ........................

4. The last time I saw Disk was in 1995.

---> I haven't .................................

5. Why don't you come to see us during lunch ?

---> Why don't you come to see us when ..........................

6. Let's leave at the come to see us during lunch ?

---> As soon as .......................

7. This book will take me two years to write .

--> In two years' time .......................

8. What 's your opinion of my essay ?

--> What do ........................

9. Nigel keeps interrupting me

----> Nigel is .........................

10. There's a smell of onions in this room.

---> This room .....................

mình đang cần gấp chiều phải nộp rùi !!

1 phân tử ADN có chiều dài 5100 hỏi phân tử trên mã hóa bao nhiêu amin tren phân tử protein chưa hoàn chỉnh và hoàn chỉnh

một gen có 3000 nu nếu gen đó cấu trúc chuỗi polipeptit thì cần môi trường cung cấp bao nhiêu aa ? Phân tử protein hoàn chỉnh đó có bao nhiêu aa?

giải phương trình sau

3(x-1)(2x-1)= 5(x+8)(x-1)

Giải phương trình sau: