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12 tháng 5 2019

 Vì \(x\ne96\Rightarrow x-96\ne0\)

a) Để A lớn nhất \(\Leftrightarrow\frac{2018}{x-96}\)lớn nhất 

                          \(\Leftrightarrow x-96\)nhỏ nhất và x là số nguyên dương bé nhất

Dấu "=" xảy ra  \(\Leftrightarrow x-96=1\)

                         \(\Leftrightarrow x=97\)

Thay x=95 vào A ta được \(A=\frac{2018}{x-96}=\frac{2018}{97-96}=2018\)

Vậy Max A =2018 \(\Leftrightarrow x=97\)

b) Để A nhỏ nhất \(\Leftrightarrow\frac{2018}{x-96}\)nhỏ nhất 

                           \(\Leftrightarrow x-96\)lớn nhất và x là số nguyên âm lớn nhất

Dấu "=" xảy ra     \(\Leftrightarrow x-96=-1\)

                            \(\Leftrightarrow x=95\)

Thay x=95 vào A ta được \(A=\frac{2018}{x-96}=\frac{2018}{95-96}=-2018\)

Vậy Min A=-2018 \(\Leftrightarrow x=95\)

12 tháng 5 2019

Câu a sửa giùm anh nhé Thay x = 95 thì thành Thay x=97 nhá

1.S    Vì có tế bào hồng cầu ko có nhân

2.S     Vì khi lớn lên do tăng số lượng tế bào

3.Đ     Vì đêm caaythair ra CO\(_2\)gây ngột thở

# Lieutenant DM #

12 tháng 5 2019

Đề bài: SO SÁNH

12 tháng 5 2019

Đặt \(A=\frac{10^{2018}+5}{10^{2018}-8};B=\frac{10^{2019}+5}{10^{2019}-8}\)

Ta có : \(A=\frac{10^{2018}+5}{10^{2018}-8}=\frac{10^{2018}-8+13}{10^{2018}-8}=1+\frac{13}{10^{2018}-8}\)

           \(B=\frac{10^{2019}+5}{10^{2019}-8}=\frac{10^{2019}-8+13}{10^{2019}-8}=1+\frac{13}{10^{2019}-8}\)

Vì \(\frac{13}{10^{2018}-8}>\frac{13}{10^{2019}-8}\)

\(\Rightarrow1+\frac{13}{10^{2018}-8}>1+\frac{13}{10^{2019}-8}\)

\(\Rightarrow A>B\)

12 tháng 5 2019

I. Mở bài: giới thiệu mùa hè
Tạo hóa đã tạo nên 4 mùa: xuân, hạ, thu và đông. Mỗi mùa đều mang một đặc trưng riêng, một cảm nhận riêng về thiên nhiên và con người. mỗi mùa có sự khác nhau về khí hậu, cây cối,… chính vì thế mà chúng ta phân biệt chúng một cách rõ rệt hơn. Trong 4 mùa em thích nhất là mua hè, mùa hè mang lại sự tươi mát, mới mẻ. Nhắc đến mùa hè ai cũng nghĩ đến sự nghĩ ngơi, giải trí và tận hưởng.

II. Thân bài: tả mùa hè
1. Tả cảnh vật mùa hè

- Bầu trời trong xanh
- Nắng chiếu chói chang
- Mây trôi nhẹ nhàng
2. Tả bao quát mùa hè
- Bắt đầu từ tháng 6 đến tháng 9
- Phượng nở báo hiệu mùa hè đến
- Ve ve kêu
- Nắng chói chang, oi bức
3. Tả chi tiết màu hè
a. Con người:
- Học sinh nghỉ hè
- Người lớn vẫn đi lam bình thường
- Chuẩn bị bắt đầu một kì nghỉ dài cho học sinh
b. Cây cối và con vật
- Buổi sang: 
+ ánh mặt trời lên cao
+ từng tia nắng chiếu xuống mặt đường 
- Buổi trưa:
+ ánh nắng rất gay gắt
+ ai cũng ngại ra đường
- chiều tà:
+ Nắng rớt
+ Hoàng hôn bao phủ khắp mọi nơi
+ Gió vi vu trên những cành cây cao làm mát hơn lúc trưa

III. kết bài: nêu cảm nghĩ về mùa hè
- Em rất thích mùa hè
- Mùa hè mang lại sức song mới và giải trí cho những ngày học mệt mỏi

~ Study well ~

✰ᗪɾɑɕυɭɑ✰

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#ĐinhBa

18 tháng 9 2019
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I. Choose the word whose underlined part is pronounced differently from that of the others1. A. load B. monkey C. home D. most2. A. develops B. cars C. meets D. books3. A. walks B. kisses C. dances D. boxes4. A. honest B. hour C. honour D. humour5. A. Internet B. ready C. every D. teeth6. A. tenth B. math C. brother D. theater7. A. pyramid B. Sydney C. dry D. hungry8. A. energy B. electricity C. effect D. environment9. A. pollution B. solar C. symbol D. reason10. A. president B. sea C. country...
Đọc tiếp

I. Choose the word whose underlined part is pronounced differently from that of the others

1. A. load B. monkey C. home D. most

2. A. develops B. cars C. meets D. books

3. A. walks B. kisses C. dances D. boxes

4. A. honest B. hour C. honour D. humour

5. A. Internet B. ready C. every D. teeth

6. A. tenth B. math C. brother D. theater

7. A. pyramid B. Sydney C. dry D. hungry

8. A. energy B. electricity C. effect D. environment

9. A. pollution B. solar C. symbol D. reason

10. A. president B. sea C. country D. about

II. Choose the best word or phrase to complete the following sentences. (4points)

1. The Pacific Ocean is ________ ocean in the world.

A. big B. the biggest C. the bigest D. bigger

2. We do ________ every morning.

A. jogging B. aerobics C. table tennis D. picnic

3. ________ I don't like vegetables, I eat them every day.

A. But B. Although C. Because D. but

4. You have to throw the ball into the net when you play ________ .

A. basketball B. football C. tennis D. badminton

5. ________ Liz buy a lot of souvenirs for her friends?

A. Did B. Do C. Were D. Is

6. ________ to a native speaker of English, Phuong?

A. Have you ever talked B. Do you ever talk

C. Did you ever talk D. Are you ever talking

7. We sometimes ________ out when we lived in the city.

A. eat B. will eat C. have eaten D. ate

8. Amsterdam is one of the _______cities in the world.

A. peacefullest B. peacefuller C. most peaceful D. more peaceful

9. I think Seoul is ______ than Jakarta.

A. cleaner B. cleanest C. more cleaner D. most cleanest

10. Fish were among the earliest forms of life. Fish ________ on earth for ages and ages.

A. will exist B. are existing C. existed D. have existed

11. In England, children ____________ go to school between the ages of 6 and 18. It is compulsory

A. should B. need C. may D. must

12. My father is fond of sports. He goes to the Sports Club to watch _____________every Saturday.

A. racing horses B. race horse C. horse races D. horsing race

13. You ___________be home before dark because it is dangerous to walk home alone at night.

Đề số 1

 

A. might B. may C. ought D, must

14. We should use reusable water bottle ____________of plastic one.

A. because B. instead C. despite D, however

15. The bear _________you if you ______________it.

A.attacks/ provoke B. will attack/ provoke

C. attacks/ will provoke D. will attack/ will provoke

16.I first_______________ Ho Chi Minh City in 2013.

A. go B. went C. visited D. been to

17 If the ______________ is polluted, we won’t have enough food to eat.

A. water B. air C. noise D. soil

18. We should give unused clothes to_____________to help the people in need.

A. charity B. factory C. market D. hospital

19. My head hurts. I need to take a ……….

A. sun cream B. backpack C. walking boots D. painkiller

20. She is always… at school. She spends most of the time studying

A. hard-working B. careful C. lazy D. funny

III. Supply the correct form of the verbs in brackets (1 point).

1. Why you (look) ...................................at me like that? What is the matter?

2. What are you doing this everning?

- I (do) ……………................... my homework, and then I (watch)...................................TV.

3. Many people in our street have cars but my parents (not have).............. one. They (like)..............to

go to work by bus.

4. When my brother and I (be)......................small, we (go) ……......… swimming every weekend.

5. Nam (not do)........................................his homework yet..

IV. Put the correct form of the word in brackets (1 point)

1. New York is an ….....………..city with many skyscrapers. (excite)

2. There are many modern ……................................….. in ho Chi minh City. (build)

3. William Shakespeare (1564-1616) is a famous.................................in the world . (fame)

4. Britain's most common leisure ………are watching TV and films and listening to the radio. (act)

5. Merlion is a ………. ............with the head od a lion and the body of fish. (create)

V.There is one mistake in each sentence. Find and correct it. (1 point)

1. I can see there is a vase behind of the light..

2. Ho Chi Minh is croweder than Da Nang City.

3. They won't going to the Time Square to welcom the New Year.

4. You should always to tell an aldult where you are going.

5. Remember to wash and ironing your own clothes every day.

VI. Fill each gap in the passage with a suitable word (3 points).

Viet Nam is in the South – East Asia. It has (1) …… ............of beautiful mountains, rivers

and beaches. (2) ….......… are two long (3) ……… in Viet Nam: the Red River in the north and the

Mekong River in the (4) ……. ..........The Mekong river is the (5).....................river in the South –

East Asiaand of course it is longer (6) …..….the Red River. the Mekong River starts in Tibet and

(7) …………. to the East Sea. Fasipan is (8) ……. highest mountain in Viet Nam. It's 3,143 meters

(9) ……… . Viet nam also has many nice (10) ……. .....................such as tra Co, sam Son, Nha

Trang, Vung Tau

 

VII. Choose the best answer for each gap in the passage (2 points).

Oak city is a great city. There’s so (1) ………………to do! There are cinemas, parks and

discos. It’s got some great clothes and music shops (2) ………………Oak city is very modern and

beautiful. There aren’t any (3) ………………buildings and there’s some beautiful

(4) ………………around the city. Is there any pollution in the Oak city? There isn’t much pollution

(5) ………………there isn’t much traffic. Everyone travels (6) ………………bike and walks, so

there aren’t many accidents. No one works, so everyone has got a lot of free time. Are there any

unfriendly people in Oak city? – No, so come and spend a little time here.

1. A. much B. many C. some D. any

2. A. neither B. either C. too D. so

3. A. beautiful B. ugly C. pretty D. unpleasant

4. A. scenery B. scene C. view D. sight

5. A. so B. because C. although D. if

6. A. so B. in C. with D. by

VIII. Finish each of the following sentences in such a way that it means exactly the same as the

sentence printed before it (3 points).

1. There are three interesting films on VTV3 today.

Today VTV3 has. ......................................….. …………………….…………

2. There are many flowers in our garden.=> Our garden……………………………………………..

3. Hue's house is near the river.. => Hue's house isn't ………………………………………………..

4. Viet Nam has lots of beautiful lakes in Viet Nam.

=>There …………………………………………………………….

5. Da Nang is smaller than Ha Noi. and Ha Noi is smaller than Ho Chi Minh City.

=>Ho Chi Minh City is the………… ………………………………………………

6. Many tourists want to visit Sa Pa because of its fresh air.

=>Many tourists want to visit Sa Pa because …………………………………………

7. Remember to do your homework..=> You must …………………………………………………..

8. A man in Sri Lanka watches TV more than any other man in the world.

=>Nobody. …………………………………………………………………………

9. We do a lot of outdoor activities in summer. => We take part in …………………...…………….

10. I won't be able to do anything unless I have a quiet room.

=>If ………………………………………………………………

IX. Use the given words or phrases to make the meaningful sentences (1,5 points)

1. future/ robots/ able/ do/ many/ things/ like/ humans//.

……………………………………………………………………………………

2. I/ go library/ last night/ and/ probably/ go/ there/ tonight/ too//.

……………………………………………………………………………………

3. There/ might/ not/ meeting/ this afternoon/ because/ director/ ill//.

……………………………………………………………………………………

4. Where/ new/ remote control/ that/ I/ buy/ last week//?

……………………………………………………………………………………

5. Hoa/ like/ eat/ noodles/ but/ mother/ always/ cook/ rice/ her//.

……………………………………………………………………………………

X. Make questions for the underlined part (1,5 points).

1. ……………………………………………………………………………… ?

 

Tom put the remote control on the bookshelf.

2. ……………………………………………………………………………… ?

They go to the English club twice a week.

3. ……………………………………………………………………………… ?

She missed a week's lessons because of illness.

4. ……………………………………………………………………………… ?

That newsreader usually gets to work by bus.

5. ……………………………………………………………………………… ?

The game show lasted for two hours and a half.

ĐỀ THI CHỌN HỌC SINH NĂNG KHIẾU LỚP 6 THCS

NĂM HỌC: 2016-2017

MÔN : TIẾNG ANH (Chương trình 10 năm)

I. Choose the word whose underlined part is pronounced differently from that of the others.(2)

1. A. chairs B. sofas C. rooms D. sinks

2. A. photo B. going C. brother D. home

3. A. school B. teaching C. chess D. chalk

4. A. cold B. volleyball C. telephone D. open

5. A. meat B. reading C. bread D. seat

6. A. writes B. makes C. takes D. drives

7. A. never B. often C. when D. tennis

8. A. eating B. reading C. teacher D. breakfast

9. A. Thursday B. thanks C. these D. birthday

10. A. surround B. counting C. country D. about

II. Choose the best word or phrase to complete the following sentences. (4points)

1. You can watch Harry Potter on TV ________ you can read it.

A. so B. and C. but D. or

2. “- ________ a nice T-shirt, Trang!” _ “ Thank you”

A. How B. What C. Which D. It

3. “- ________ films have you seen this week ?” _ “ Only one”

A. How many B. What C. Which D. Who

4. There aren’t - ________ good films on TV at the moment.

A. some B. any C. much D. a lot

5. If we cut down more trees, there - ________ more floods.

A. are B. were C. have been D. will be

6. That is - ________ book I’ve ever read.

A. the borest B. the boring C. the most boring D. the most bored

7. I’ ve never seen a- ________ bridge than this one.

A. longest B. longer C. most longest D. more longer

8. That dog isn’t _______it looks.

A. more dangerous than B. as dangerous as

C. dangerous than D. dangerouser than

9. In the future, we won’t go on holiday to the beach but we - ______ go on holiday to the moon.

A. must B. can’t C. might D. won’t

10. - ________ you swim when you were ten?

Đề số 2

 

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

11. My father likes watching TV____________ he doesn’t like listening to music.

A. and B. so C. but D. because

12. We should use _____________pens and pencils to reduce rubbish.

A. reliable B. reusable C. refillable D. sociable

13. In the future, we will have ___________to do housework.

A. robots B. wireless TV C. smart phone D, hi-tech fridge

14. Eiffel Tower is the most attractive ____________in France.

A. building B. resor C. square D, landmark

15. We should use _________to save natural resources.

A. oil B. solar energy C. coal D. gas

16._______________ means creating new products from used materials.

A. Reduce B. Reuse C. Recycle D. Rebuild

17 If the ______________ is polluted, we won’t have enough food to eat.

A. water B. air C. noise D. soil

18. We should give unused clothes to_____________to help the people in need.

A. charity B. factory C. market D. hospital

19. My head hurts. I need to take a ……….

A. sun cream B. backpack C. walking boots D. painkiller

20. She is always… at school. She spends most of the time studying

A. hard-working B. careful C. lazy D. funny

10
21 tháng 5 2019

I. Choose the word whose underlined part is pronounced differently from that of the others

1. A. load B. monkey C. home D. most

2. A. develops B. cars C. meets D. books

3. A. walks B. kisses C. dances D. boxes

4. A. honest B. hour C. honour D. humour

5. A. Internet B. ready C. every D. teeth

6. A. tenth B. math C. brother D. theater

7. A. pyramid B. Sydney C. dry D. hungry

8. A. energy B. electricity C. effect D. environment

9. A. pollution B. solar C. symbol D. reason

10. A. president B. sea C. country D. about

21 tháng 5 2019

II. Choose the best word or phrase to complete the following sentences. (4points)

1. The Pacific Ocean is ________ ocean in the world.

A. big B. the biggest C. the bigest D. bigger

2. We do ________ every morning.

A. jogging B. aerobics C. table tennis D. picnic

3. ________ I don't vegetables, I eat them every day.

A. But B. Although C. Because D. but

4. You have to throw the ball into the net when you play ________ .

A. basketball B. football C. tennis D. badminton

5. ________ Liz buy a lot of souvenirs for her friends?

A. Did B. Do C. Were D. Is

6. ________ to a native speaker of English, Phuong?

A. Have you ever talked B. Do you ever talk

C. Did you ever talk D. Are you ever talking

7. We sometimes ________ out when we lived in the city.

A. eat B. will eat C. have eaten D. ate

8. Amsterdam is one of the _______cities in the world.

A. peacefullest B. peacefuller C. most peaceful D. more peaceful

9. I think Seoul is ______ than Jakarta.

A. cleaner B. cleanest C. more cleaner D. most cleanest

10. Fish were among the earliest forms of life. Fish ________ on earth for ages and ages.

A. will exist B. are existing C. existed D. have existed

11. In England, children ____________ go to school between the ages of 6 and 18. It is compulsory

A. should B. need C. may D. must

12. My father is fond of sports. He goes to the Sports Club to watch _____________every Saturday.

A. racing horses B. race horse C. horse races D. horsing race

13. You ___________be home before dark because it is dangerous to walk home alone at night.

A. might B. may C. ought D, must

14. We should use reusable water bottle ____________of plas one.

A. because B. instead C. despite D, however

15. The bear _________you if you ______________it.

A.attacks/ provoke B. will attack/ provoke

C. attacks/ will provoke D. will attack/ will provoke

16.I first_______________ Ho Chi Minh City in 2013.

A. go B. went C. visited D. been to

17 If the ______________ is polluted, we won’t have enough food to eat.

A. water B. air C. noise D. soil

18. We should give unused clothes to_____________to help the people in need.

A. charity B. factory C. market D. hospital

19. My head hurts. I need to take a ……….

A. sun cream B. backpack C. walking boots D. painkiller

20. She is always… at school. She spends most of the time studying

A. hard-working B. careful C. lazy D. funny

11 tháng 5 2019

I have studied English for three years.

-> I began studying English three years ago.

~Study well~

#Seok_Jin#

I began to stdy three years ago

VC
11 tháng 5 2019

Xí nghiệp đó may được số bộ quần áo là

250 x (100% + 12% 0 = 280 ( bộ )

Đáp số : 280 bộ quần áo

11 tháng 5 2019

số sản phẩm vượt mức là

250 nhân 12% = 30 (SP)

tổng sản phẩm may được

250+30=280(SP)

DS:......

tích nhaaaaaaaa

11 tháng 5 2019

a) Có : \(\widehat{xOy}\) và \(\widehat{yOz}\)là hai góc ở vị trí kề nhau

=> \(\widehat{xOy}+\widehat{yOz}=\widehat{xOz}\)

       \(30^o+\widehat{yOz}=60^o\)

=> \(\widehat{yOz}=60^o-30^o=30^o\)

b) Có : \(\widehat{xOz}\)và \(\widehat{tOz}\)là 2 góc kề bù 

=> \(\widehat{xOz}+\widehat{tOz}=180^o\)

       \(60^o+\widehat{tOz}=180^o\)

=> \(\widehat{tOz}=180^o-60^o=120^o\)

11 tháng 5 2019

c) Lại có Om là tia p/g của \(\widehat{tOz}\)

=> \(\widehat{tOm}=\widehat{zOm}=\frac{1}{2}.\widehat{tOz}\) \(=\frac{1}{2}.120^o=60^o\)

Có :  \(\widehat{tOm}=60^o\)        ;            \(\widehat{xOz}=60^o\)       

=> \(\widehat{tOm}=\widehat{xOz}\)

d) Có \(\widehat{tOm}=\widehat{zOm}\)( do Om là tia p/g của \(\widehat{zOt}\))

mà \(\widehat{tOm}=60^o=>\widehat{zOm}=60^o\)

Ta lại có : \(\widehat{xOz}\) = \(\widehat{zOm}\left(=60^o\right)\)

mà hai góc này kề nhau 

nên Oz là tia p/g của \(\widehat{xOm}\)

Bạn tham khảo tại đây nhé !!!

https://olm.vn/hoi-dap/detail/36814335864.html

 

Gọi số phải tìm là xy7, theo đề bài ta có :

2xy7 + 21 = 7xy

\(\rightarrow\) 2 ( 100x + 10y + 7 ) + 21 = 700 + 10x + y

Sau khi rút gọn ta được : 10x + y = 35 \(\rightarrow\)xy = 35

Vậy số phải tìm là 375

#ĐinhBa