trần thị diệu linh

1. ........she have a good time with her grandparent last time?

A. Was B. Did C. Does D. Will

2. Hung ran .......fast that he broke the world record

A. So B. Too C. Much D. Such

3. She often ........swimming with her friends in summer

A. Go B. Goes C. Went D. Gone

4. Hoa wishes she .....the exam with high score

A. Passes B.pass C. Passed D. Will pass

5. What was your brother doing when Jim........at 5 p.m yesterday?

A. Come B. Had come C. Came D. Would come

6. It's very kind ......you to help me

A. On B. Of C. In D. For

7.there is not .........for us to live in her house. It's only 40 square meters.

A. Room enough B. Enough room

C. Big enough D. Enough large

8. My parents....to Ha Noi 5 years ago

A. Move B. Moves C. Moving D.Moved

9. I wish i ......pass the mid- term test today

A. Will B. Could C. Can D. May

10. This school needs ......before the beginning of a new semester

A. To repaint B. To be repainting

C. Repainting D. Repainted

11. The boy ......next to me is my cousin

A. Sits B. Sit C. Sat D. Sitting

12. If only i .......soon, i wouldn't miss the train

A. Arrived B. Arrive C. Arriving

D. Arrives

13. You should do your homework.........

A. By yourself B. By your

C. Your own D. Myself

Đọc đề xong kiểu sang chấn tâm lí, rơi vào trầm tư :< Đã có quá nhiều sự random trong bài làm của mình oimeoi =((

Complete the sentences with Presnt simple or the present continuous form of the verbs .

1 : They often (visit) ...visit... their parents in the holidays.

2: We ( speeak ) ...are speaking... french at the moment

3: I ( watch ) ..watch...... TV about 3 hours a day.

4 : My family usually (go ) ...goes....... to the movies on sunday .

5 : Look at the girl! She ( ride ) ...is riding....a horse .

6 : We ( play) ....are playing..... tennis now .

7: Minh sometimes (practice)...pratices.........the guitar in his room.

8:..Do.... you (like)....like.......chocolate ice cream ?

9: I really ( like ).....like..........cooking .

10 : hung can't answer the phone because he (take )....is taking....a shower.

\(a,x^2\left(x-5\right)+5-x=0\\ \Leftrightarrow x^2\left(x-5\right)-\left(x-5\right)=0\\ \Leftrightarrow\left(x^2-1\right)\left(x-5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=1\\x=-1\\x=5\end{matrix}\right.\)

\(b,3x^4-9x^3=-9x^2+27x\\ \Leftrightarrow3x^4-9x^3+9x^2-27x=0\\ \Leftrightarrow3x^3\left(x-3\right)+9x\left(x-3\right)=0\\ \Leftrightarrow3x\left(x-3\right)\left(x^2+2\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)

do \(x^2+2>0\)

\(c,x^2\left(x+8\right)+x^2=-8x\\ \Leftrightarrow x^2\left(x+8\right)+x^2+8x=0\\ \Leftrightarrow x^2\left(x+8\right)+x\left(x+8\right)=0\\ \Leftrightarrow x\left(x+1\right)\left(x+8\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\\x=-8\end{matrix}\right.\)

\(d,\left(x+3\right)\left(x^2-3x+5\right)=x^2+3x\\ \Leftrightarrow\left(x+3\right)\left(x^2-3x+5\right)-x^2-3x=0\\ \Leftrightarrow\left(x+3\right)\left(x^2-3x+5\right)-x\left(x+3\right)=0\\ \Leftrightarrow\left(x+3\right)\left(x^2-3x+5-x\right)=0\\ \Leftrightarrow\left(x+3\right)\left(x^2-4x+5\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=-3\\x^2-4x+5=0\end{matrix}\right.\)

\(\Delta=b^2-4ac=\left(-4\right)^2-4\cdot1\cdot5=16-20=-4< 0\)\(\rightarrow\)\(x^2-4x+5\) vô nghiệm

Vậy \(x=-3\)

a) \(\frac{x}{5}=\frac{2}{5}\Rightarrow x=\frac{2\cdot5}{5}=2\)

b)\(\frac{3}{8}=\frac{6}{x}\Rightarrow x=\frac{6\cdot8}{3}=16\)

c)\(\frac{1}{9}=\frac{x}{27}\Rightarrow x=\frac{27}{9}=3\)

d) \(\frac{4}{x}=\frac{8}{6}\Rightarrow x=\frac{4\cdot6}{8}=3\)

e)

\(\frac{3}{x-5}=-\frac{4}{x+2}\\ \Rightarrow3\left(x+2\right)=-4\left(x-5\right)\\ \Leftrightarrow3x+6=-4x+20\\ \Leftrightarrow3x+6+4x-20=0\\ \Leftrightarrow7x-14=0\\ \Leftrightarrow x=2\)

\(g,\frac{x}{-2}=-\frac{8}{x}\Rightarrow x^2=16\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-4\end{matrix}\right.\)

Vậy có 2 giá trị của x là 4 ; -4

a) Ta có:

\(x\left(5x-3\right)-x^2\left(x-1\right)+x\left(x^2-6x\right)-10+3x\\ =5x^2-3x-x^3+x^2+x^3-6x^2-10+3x\\ =-10\)Vậy giá trị của các biểu thức trên không phụ thuộc vào gt của biến

b) Ta có:

\(x\left(x^2+x+1\right)-x^2\left(x+1\right)-x+5\\ =x^3+x^2+x-x^3-x^2-x+5\\ =5\)

Vậy..........

\(\left(\sqrt{20}-\sqrt{45}+\sqrt{5}\right)\sqrt{5}\\ =\left(2\sqrt{5}-3\sqrt{5}+\sqrt{5}\right)\sqrt{5}\\ =\sqrt{5}\)

Mình trả lời tiếp câu b nhó, nãy mình chưa trả lời câu b thì lỡ bấm nút mất tiu :<

b)

Xét trong \(\Delta\)vuông ABC có:

\(CosC=\frac{2}{3}\Rightarrow\widehat{C}\approx48^o\\ \Rightarrow AC=AB\cdot tanC=6\cdot tan48^o\approx6,66\left(cm\right)\\ BC=\frac{AC}{CosC}=\frac{6,66}{Cos48^o}\approx9,95\left(cm\right)\)

a) Trong \(\Delta\) vuông ABH có:

\(AB=\frac{BH}{CosB}=\frac{4}{Cos60^o}=8\left(cm\right)\)

Tương tự trong \(\Delta\)vuông ABC có:

\(BC=\frac{AB}{CosB}=\frac{8}{Cos60^o}=16\left(cm\right)\\ AC=BC\cdot SinB=16\cdot Sin60^o=8\sqrt{3}\left(cm\right)\)

Read the passage .The dedicate the following sentences are True ,False

The internet has rapidly developed and become part of our daily life . It's a very fast and convenient way to get information . people use the internet for many purposes : education , communication , entertainment and commerce . the internet helps people communicate with friends and relatives by means of email or chatting. However , the internet has limitations . It is time - consuming and costly . It is also dangerous because of viruses and bad programs . besides , the internet users sometimes have to suffer various risks such as spam or electronic junk mail and personal information leaking . so , while enjoying surfing , be alert

1.The internet has slowly developed nowadays

-> F

2.People use the internet to get information

->T

3.More people use the internet for education

->T

4.The internet can't help people communicate with friends and relatives

-> F

5.viruses and bad programs are dangerous for the internet users

-> T

6.the internet users shouldn't spend a lot of time surfing the web a day

->T

Ui contest hứp dẫn rứa :3

Chừng nào hết hạn rứa ọ :v

Vì có nền địa hình cao, mùa đông lạnh

\(S=\frac{2a+2ab-b-1}{3b\left(2a-1\right)+6a-3}\\ =\frac{2a\left(b+1\right)-\left(b+1\right)}{3b\left(2a-1\right)+3\left(2a-1\right)}\\ =\frac{\left(2a-1\right)\left(b+1\right)}{3\left(b+1\right)\left(2a-1\right)}\\=\frac{1}{3}\)

find one mistake in each line of the following sentences and correct it

1 . He is advised to watering the garden every day

A B C D water

2 . He enjoy fishing because it is interesting

A B C D enjoys

Put the verbs in the brackets into the correct form: infinitive with to or infinitive without to. In some senteces, both are correct.

1. I hope ....to help...... other people with their work (help)

2. He promised to phone .......... me soon (phone)

3. The student are well- prepare ....to take...... the final exam (take)

4. I'll help you ...to arrange....... the party if you like (arrange)

5. My uncle let me ...borrow....... his motorcycle while he was is on holiday (borrow)

6. The police observed a man ....enter...... the bank (enter)

7. Tuan is sure ..will........ the English speaking contest (will)

8. Children should be let ...play....... freely (play)

9. Did you hear him .... go...... out? (go)

10. The first man .to set......... foot on the moon is Neil rmstrong (set)

11. We weren't allowed ...to enter....... the restricted area (enter)

12. They didn't let us ..enter........ the retricted area (enter)

13. I felt someone ....walk...... into the room (walk)

Gạch chân và sủa lỗi sai

1.I havegot an mouth =>....an -> a .....................

2.What colour are they ? They are pinks =>....colour -> colours..........

3.Is it a shirt ? No, it is.It is a jumper =>.it is -> it isn't..................

4.Let count =>..Let -> Let's......

5.How many lemon ? two lemons =>.....lemon -> lemons.........

1.The road was _____ away during the storm last night.

A. flooded B.flowed C.washed D.over

2._____ many times I tell him, he always forgets to pass on phone messages.

A.Wherever B.Whatever C.However D.Whenever

3.This sort of music was very _____ in the 1960s.

A.preferred B.liked C.favourite D.popular

4.They'll never ______ to get here by six; the roads are quite busy today.

A.manage B.arrive C.succeed D.able

5.The instructor warned the students _______ swimming alone in the pool.

A.not B.from C.about D.out of

6.Sam was accused of stealing some _______ documents from the safe.

A.confidence B.confidential C.confiding D.confided

a)

\(x-\sqrt{x}-\sqrt{xy}+\sqrt{y}\\ =\sqrt{x}\left(\sqrt{x}-1\right)-\sqrt{y}\left(\sqrt{x}-1\right)\\ =\left(\sqrt{x}-1\right)\left(\sqrt{x}-\sqrt{y}\right)\)

b)

\(\sqrt{xy}-4\sqrt{x}+3\sqrt{y}-12\\ =\sqrt{x}\left(\sqrt{y}-4\right)+3\left(\sqrt{y}-4\right)\\ =\left(\sqrt{y}-4\right)\left(\sqrt{x}+3\right)\)

a)

\(4x+12\sqrt{x}\cdot\sqrt{y}+9y\\ =\left(2\sqrt{x}\right)^2+2.2.3\cdot\sqrt{x}\cdot\sqrt{y}+\left(3\sqrt{y}\right)^2\\ =\left(2\sqrt{x}+3\sqrt{y}\right)^2\)

b)

\(\frac{x}{4}-\sqrt{x}\sqrt{y}+y\\ =\left(\frac{\sqrt{x}}{2}\right)^2-2\cdot\frac{\sqrt{x}}{2}\cdot\sqrt{y}+\left(\sqrt{y}\right)^2\\ =\left(\frac{\sqrt{x}}{2}-\sqrt{y}\right)^2\)

d)

\(\sqrt{x^2-9}-3\sqrt{x-3}\\ =\sqrt{\left(x-3\right)\left(x+3\right)}-3\sqrt{x-3}\\ =\sqrt{x-3}\sqrt{x+3}-3\sqrt{x-3}\\ =\sqrt{x-3}\left(\sqrt{x+3}-3\right)\)

Complete the sentences with the adjectives from the box.

generous peaceful optimistic quiet inconvenient
fresh brave exciting vast skillful envious

1. It’s ____exciting ________ to see a kite flying high in the sky.
2. It was very ____quiet________ there; you could just hear the wind moving in the trees.
3. I love the ____vast ________ open spaces and the ___fresh_________ air in the countryside.
4. The villagers often find it _____inconvenient_______ to get into town due to the lack of public transport.
5. People in rural areas are more ___optimistic

________ than their city counterparts.
6. I’m so __envious__________ of you getting such an exciting holiday.
7. Billy is clearly a __generous__________ person. He contributed lots of money to charity.
8. It was very _brave___________ of him to jump into the river to save a drowning child,.
9. Most of Mongolian people are _____skillful_______ at riding a horse.
10. Life in the countryside is more _ peaceful ___________ and healthier.

\(\left|x\left(x-4\right)\right|=x\\ \Leftrightarrow\left[{}\begin{matrix}x\left(x-4\right)=x\\x\left(x-4\right)=-x\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x^2-4x-x=0\\x^2-4x+x=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x^2-5x=0\\x^2-3x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x\left(x-5\right)=0\\x\left(x-3\right)=0\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}x=0\\x=5\end{matrix}\right.\\\left\{{}\begin{matrix}x=0\\x=3\end{matrix}\right.\end{matrix}\right.\)

Vậy có 3 giá trị của x là: \(x=0;\\ x=5;\\ x=3\)

bài 1, tìm lỗi sai và sửa
1, I couldn't (go to) the beach (yesterday) because (it) rained too (heavy)
A B C D -> heavily
2,they asked me (what did happen) (last night) , but i was (unable to tell) (them)
A B C D -> what happened
3, we can (save) (nature resources) (by using) (solar energy)
A B C D -> natural resources

bài 3 , viết lại câu
1, I am afraid that we have not got any eggs (run)

I'm afraid that we've run out of eggs.
2, Our new house makes me feel excited (about)

We are excited about our new house
3, Ellen didn't have enough money for the ticket (afford)

Ellen couldn't afford to buy the ticket
4, Why don't you search for this wword in the dictionary (look)

Why don't you look up this word in the dictionary?
5, the last film we saw was more frightening than this one (as)

This film is not as frightening as the last one we saw

II. Chia dạng đúng của động từ trong ngoặc

13. Last week, I decide)......decided..............to invite some friends over for dinner.

14. I am looking forward to (see)....seeing..................you again.

15. My father usually (walk).......walks...... ..............in the early mornings.

16. I (write). ..am writing................a letter to my sister at the moment

17. Three years ago, there (be).....was.... ........... very few people in this village.

18. The post office (open) .....opens................ at 8.00 everyday

III. Mỗi câu sau có một lỗi. Tìm và sửa lại cho đúng

19. Does he got a calculator?

………DOES -> HAS

20. What are you go to do tomorrow?

………GO - > GOING

21. Where you went last night?

……Where DID you GO last night?……………………………………………………...

22. Would you like going for a walk?

……GOING-> TO GO

23. Pasta comes from France

……COME-> MADE……..

24. The temperature rises at night

……RISES -> DROPS………

IV. Đọc đoạn văn và trả lời câu hỏi,

There is no doubt that the environment is in trouble. Factories bum fossil us which produce acid rain, and this kills trees. At the same time, greenhouse gases is into the wind contribute to global warming, which threatens to melt the polar ice cap. Meanwhile formats clear huge areas of rain forest in places such as the Amazon to produce feeding and for alle or produce wood for building. Rivers and oceans are so heavily contaminated by industri waste that it is no longer safe to go swimming. Cars pump out poisonous puses which we have to breathe in. Poaching and overfishing are killing off millions of animals, including whales, elephants and other endangered species. In fact, all around us, all living things are and small which comprise our finely balanced ecosystem are being systematically destroyed by human greed and thoughtlessness.

There is a lot we can do, however, to prevent this. The easiest thing, of course, is to scycle waste materials such as papers and glasses so that we can use them again. If you are truly committed to protecting the environment, of course, you should only buy organic fruits and vegetables, safe in the knowledge that they have been naturally cultivated. Finally, we should buy a small car that uses unleaded petrol which is less harmful to the environment or even better, make more use of public transport, 25. According to the text, what kills trees?

26. Why are rivers and oceans no longer safe enough to swim in ?

Because rivers and oceans are so heavily contaminated by industri waste that it is no longer safe to go swimming.

27. According to the text, which animals are considered endangered?

whales, elephants and other endangered species.

28. In general, what is destroying our ecosystem?

human greed and thoughtlessness.

29. According to the text, what can we do to protect the environment?

-scycle waste materials such as papers and glasses so that we can use them again

-We should only buy organic fruits and vegetables, safe in the knowledge that they have been naturally cultivated.

we should buy a small car that uses unleaded petrol which is less harmful to the environment or even better, make more use of public transport

1. It is getting dark but they don't stop working (although)

Although it is getting dark , they don't stop working

2. My mother-in-law can not come with us because she is ill (If clause)

If my mother -in-law wasn't ill, she could come with us

3. Henry is collecting plastic bags and tins (Passive voice)

Plastic bags and tins is being collected by Henry

4. Father's secrets were discovered by my mother (Change into active voice)

My mother discovered Father's secrets

5. Because the driver was careless, the pity accident happended (Because of)

Because of careless driving, the pity accident happened

6. The flat where my aunt lives in is very nice (correct mistake)

in - > \(\varnothing\)

7. The woman whose live next door is an actress

live -> lives

8. Colin lives in the countryside now, didn't he?

didn't -> doesn't

9. The restaurant _where_____ caught fire has been rebuilt (relative clause)

10. Although my husband rarely has desert, i prefer cakes to fruits (correct mistake)

desert -> dessert

11. My sister can type very well, and neither do i (correct mistake)

neither -> So

12. The football match is very excited (correct mistake)

excited -> exciting

13. The man who you are talking is my cousin (correct mistake)

who -> whom

14. If our 3 years old daughter spoke English well, we will be very happy (correct mistake)

will -> would

15. Our university is between the banks or the supermarket (correct mistake)

or -> and

16. Hoa jumped up from the tree by the river (correct mistake)

by - > to

17. There are two woman and a man in the metting (correct mistake)

woman -> women

18. Her younger sister fell out in bed (correct mistake)

out -> off

19. When you look down you can see the sun (correct mistake)

down -> up ( mình không chắc lắm , vì nhìn lên mới thấy mặt trời chứ? )

I)Conditional sentences

1.If the earth suddenly (stop)..stopped. spinning we all (fly)would fly....off it.

2.If you (smoke).smoke..in a non-smoking compartment the other passengers (object).will object...

3.(your parents/not/be)..Weren't your parents......proud if they could see you now?

4.I'm broke,but I (have)..would have...plenty of money now If I (not/spend).hadn't spend...so much yesterday

5.If we (work)worked...all right, we (finish).would finish...in time; but we have no intention of doing it

6.If we (have)..had...a submarine now, we (use).would use... it to investigate the seabed

7.Were he ten years younger, he (take)...would take...part in the voyage around the world

8.Should you come late, they (not,let)..won't let...you in

9.He might get rid of his cough if he (not smoke).DIND'T SMOKE...so much

10.If someone (give)..GAVE... you a boat what WOULD you (do)..DO .?

11.Water (freeze).WILL FREEZE...if the temperature falls below zero

12.I (warn).WOULD HAVE WARNED...you if I had seen you last week

13.He always says hello if he (see)..SEES.you

14.What would you do if he (resign)..RESIGNED ...tomorrow?

15.I wouldn't have seen so upset if Judy (write).HAD WRITTEN..to me earlier

16.Shout if you (see)..SEE..anything unusually

17.The engine starts if you (turn).TURN..this key

18. If he weren't so bad temperature, his wife (not leave)..WOULDN'T LEAVE...him so soon after the marriage

19.What (you/say)..WOULD YOU SAY.....if I offered you a job?

20.I can't help feeling sorry for the hungry children. If only there (be)..WERE...peace in the world

21.Were I to become president, my first act(be).WOULD BE... to help the poor

22.I feel as if my head(be)..WERE...on fire now, doctor.

Áp dụng quy tắc hóa trị ta có:

\(I\cdot z=II\cdot y\\ \Rightarrow\frac{z}{y}=\frac{II}{I}\\ \Rightarrow z=2;y=1\)

Vậy công thức của hợp chất là : \(Na_2SO_4\)

EX2 : change from althought / though / enen though - in spite of / despite , starting as available

1. although he was tired , he walked to the station

....Despite being tired,.he walked to the station.... ..............................................................

2. they went swimming in spite of the coldness of the water

............Although the water was cold, the went swimming...................................................

3. in spite of being bad at pool , she beat him three times in a row

Although she was bad at pool, she beat him three times in a row

4. she decided to go abroad for a year despite loving her boyfriend very much

...She decided to go abroad for a year although she loved her boy friend very much

5. he want on holiday to thailand in spite of the expensive airfare

.....He went on holiday to Thailand although the airfare was expensive

6. socrates never had much money despite being very famous in his own day

......Although Socrates was very famous in his own day, he never . had much money

7. his career did not really take off despite his ambitions

............Though he was ambitious, his career did not really take off

8. they managed to work together despite their differenses of opinion

........Though they had different opinions, they managed to work together

3. Chọn từ thích hợp trong bảng và điền vào chỗ trống

1. Ann…plays…………..handball very well.

2. I never…drink…………..coffee.

3. The swimming pool………opens……..at 7.00 in the morning.

4. It……closes………..at 9.00 in the evening.

5. Bad driving…causes…………..many accidents

6. My parents…live…………..in a very small flat.

7. My students……speak………..a little English.

8. The Olympic Games…take…………..place every four years.

9. They are good students. They always……do………..their homework.

10. I always……wake up………..early in the morning.