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20 tháng 8 2022

1 + 5 + 9 + 13 + 17 +…. + x =507528

Ta có 5 = 2 + 3; 9 = 4 + 5; 13 = 6 + 7; 17 = 8 + 9…

Suy ra x = a (a + 1) (với a ϵ N)

Nên 1 + 5 + 9 + 13 + 17 +…. + x = 1 + 2 + 3 + 4 + 5 + 6 + 7 + ….+ a (a + 1) =507528

Hay ( a + 1) (a + 1 + 1) : 2 = 1225

( a + 1) (a + 2) = 1225 x 2 = 2450  = 49 x 50 

=> a = 48 

=> x = 48 x ( 48 + 1 ) = 2352

20 tháng 8 2022

1 + 5 + 9 + 13 + 17 +…. + x =507528

Ta có 5 = 2 + 3; 9 = 4 + 5; 13 = 6 + 7; 17 = 8 + 9…

Suy ra x = a (a + 1) (với a ϵ N)

Nên 1 + 5 + 9 + 13 + 17 +…. + x = 1 + 2 + 3 + 4 + 5 + 6 + 7 + ….+ a (a + 1) =507528

Hay ( a + 1) (a + 1 + 1) : 2 = 1225

( a + 1) (a + 2) = 1225 x 2 = 2450  = 49 x 50 

=> a = 48 

=> x = 48 x ( 48 + 1 ) = 2352

19 tháng 3 2020

I. Write “a” or “an” in the space:

1. .......an.....unreasonable decision

2.......a.......universal problem

3. .....a.......unit of work

4.......a.......eucalyptus tree

5. .....an.......honorable man

6......an........X-ray

7. .... .a......UFO

8.........a.....T shirt

9. ......a......happy girl

10......an......H-bomb

11. ......an......elephant

12.....a.......hospital

13. ......a......BBC programme

14.....a.......UNESCO worker

21 tháng 3 2020

2,3,4,5,7,11,14:an(phụ âm u,e,o,a,i)

6,8,9,10,12,13:a

I. Circle best option A, B, C or D to complete the following sentences. (0.2 x 10 = 2.0 pts) 1. ……………..straight across the road. A. Don’t run B. Not run C. No run D. Can’t run 2. I learn music………………. : on Mondays and Fridays. A. two times a week B. once a week C. one a week D. twice a week 3. What is your favourite food? A. I favourite chicken B. My favourite food chicken C. Chicken favourite me D. I like chicken best. 4. Linda ……… her hair every day. A. washes B. wash C. clean...
Đọc tiếp
I. Circle best option A, B, C or D to complete the following sentences. (0.2 x 10 = 2.0 pts) 1. ……………..straight across the road. A. Don’t run B. Not run C. No run D. Can’t run 2. I learn music………………. : on Mondays and Fridays. A. two times a week B. once a week C. one a week D. twice a week 3. What is your favourite food? A. I favourite chicken B. My favourite food chicken C. Chicken favourite me D. I like chicken best. 4. Linda ……… her hair every day. A. washes B. wash C. clean D. cleans 5 .How many minutes are there in………… hour? A. a B. an C. the D. these

6. Does Mrs. Mai go to school …………car? - Yes, she does.

A. on B. in C. by D. of

7. Is he good ……….. Physics and Math?

A. for B. at C. on D. in

8. I can’t speak French but my brother ………....

A. can B. can’t C. does D. doesn’t

9. My mother always wants me ………… the piano well.

A. to play B. playing C. play D. to playing

10. Who ………… you English?

A. teach B. does teach C. do teach D. teaches

II. Use the words given in brackets to form a word that fits in the space. (0.2 x 10 = 2.0 pts))

1. The..................of this book is 2.000d (COST)

2. Don’t go out at night because it is very …………… (DANGER)

3. This exercise is very ………….. I can’t do it. (DIFFICULTY)

4. Vietnam has a lot of …… beaches. (BEAUTY)

5. Air ….. is a big problem in many cities in the world. (POLLUTE)

6. Our children sometimes go …..on the weekends. (CAMP)

7. I’m Vietnamese. What’s your ….? (NATION)

8. Mount Everest is very high. It is the ….. mountain in the world. (HIGH)

9. I visit my grandparents ..................... a month.( ONE)

10. We went to bed early because we had a ……….. day. (tire)

III.Complete the following sentences with the correct form of the verb in the brackets. (0.2 x 5 = 1.0 pts)

1. What (there/ be / drink).............................................................for dinner?

2. What.................she (like / do).........................in her spare time?

3. Why..............we( not go).....................out for a meal?

4. This job (be).................interesting. You should (apply).....................for the job.

5. ( you/ look).....................for Peter?- I think he (read).......................books in the library.

IV.Fill each gap of the following sentences with a suitable preposition. (0.2 x 5 = 1.0 pt)

1. Are you interested………… history?

2. Is she good ………… English?

3. I agree ………… you about that.

4. The beef is on the table …….. ……the eggs and the fish..

5. My father always goes to work ………… car.

D. READING.

I.Circle best option A, B, C or D to complete the following passage. (0.2 x 10 = 2.0 pts)

I live in a house near the sea. It is ...(1)... old house, about 100 years old and...(2)... very small. There are two bedrooms upstairs...(3)... no bathroom. The bathroom is downstairs ... (4)... the kitchen and there is a living room where there is a lovely old fire place. There is a garden...(5)... the house. The garden...(6)... down to the beach and in spring and summer...(7)... flowers every where. I live alone...(8)... my dog, Rack, but we have a lot of visitors. My city friends often stay with...(9)...

I love my house for... (10)... reasons: the garden, the flowers in summer.., but the best thing is the view from my bedroom window.

1 A. a B. an C. the D. any 2 A. It's B. It C. there's D. They're 3 A. and B. or C. but D. too 4 A. between B. next C. near to D. next to 5 A. in front B. front of C. of front in D. in front of 6 A. go B. going C. goes D. in goes 7 A. there are B. they are C. there is D. those are 8 A. for B. of C. on D. with 9 A. me B. I C. my D. I'm 10 A. a B. any C. many D. a lot II.Fill in each blank with ONE suitable word to complete the passage. . (0.2 x 10 = 2.0 pts) We are destroying the Earth. The seas and rivers are (1)......... dirty to swim in. There (2)............ too smoke in the air in many cities in the world, we are cutting (3)...........too many trees. We (4) ............ burning the forests. We are also destroying (5)............ of plants and (6)......... . Many areas(7)...........Earth are wasteland. Farmers in many parts of the world can not (8) ........... enoughto eat. In some countries (9).......... is too little rice. The Earth is in (10).......... . Save the Earth. Your answers: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10 III. Read the following paragraph and decide whether the statements are True (T) or False (F):(0,25 x 4 = 1.0 pt) The world cuts down more than a million trees every year to make paper and paper products . In the USA , each person uses about 300 kilograms of paper each year . In Europe , the figure is 200 kilograms . In India , each person uses only six kilograms of paper each year . It takes two tons of wood ans 200,000 litres of water to make a ton of paper . About thirty per cent of our rubbish is paper and paper products . It is better to save waste paper and other paper products and recycle them . 1 . People use more than a billion trees a year to make paper and paper products .……… 2 . People in Europe use more paper than people in the USA . ………. 3 . It takes 3 tons of wood and 200,000 litres of water a ton of paper . ……… 4 . It is good to save waste paper and recycle them . ……… E.WRITING I. Choose the underlined words or phrases that are not correct in standard written English.(0,2 x 5 = 1pt) 1.I like watching TV.There are a good film on TV tonight. A B C D 2. Whatis he often do whenit’s hot? A B C D 3.How much rooms are therein the new house? A B C D 4. I’m very thirsty. I like any apple juice. A B C D 5. How many childs does your sister have? A B C D

II. Rewrite each of the following sentences, beginning as shown, so that themeaning staysthe same.( O,2 x 10 = 2pts)

1. Is there a colorful picture in your room?

Has ………………………………………………………...…….........................?

2. How much is a bowl of noodles?

How much does .....................................................................................................

3. Let's go out for a walk.

Why .......................................................................................................................?

4. I like beef and vegetables best.

Beef .......................................................................................................................

5. That pencil belongs to Hoa.

Hoa is……………………………..........................................................................

6. What is the age of this building?.

How .................................................................................................................. …?

7. The Mekong river is longer than the Red river.

The red river …………………………………………….......................................

8. I spend two hours a day doing my homework.

It...............................................................................................................................

9. No one in my class is as beautiful as Hoa.

Hoa............................................................................................................................

10. It's often hot in the summer.

It's never.......................................................................................................

11
6 tháng 1 2018

I. Circle best option A, B, C or D to complete the following sentences. (0.2 x 10 = 2.0 pts)

1. ……………..straight across the road.
A. Don’t run B. Not run C. No run D. Can’t run
2. I learn music………………. : on Mondays and Fridays.

A. two times a week B. once a week

C. one a week D. twice a week

3. What is your favourite food?

A. I favourite chicken B. My favourite food chicken

C. Chicken favourite me D. I like chicken best.

4. Linda ……… her hair every day.

A. washes B. wash C. clean D. cleans

5 .How many minutes are there in………… hour?

A. a B. an C. the D. these

6. Does Mrs. Mai go to school …………car? - Yes, she does.

A. on B. in C. by D. of

7. Is he good ……….. Physics and Math?

A. for B. at C. on D. in

8. I can’t speak French but my brother ………....

A. can B. can’t C. does D. doesn’t

9. My mother always wants me ………… the piano well.

A. to play B. playing C. play D. to playing

10. Who ………… you English?

A. teach B. does teach C. do teach D. teaches

6 tháng 1 2018

II. Use the words given in brackets to form a word that fits in the space. (0.2 x 10 = 2.0 pts))

1. The..........price........of this book is 2.000d (COST)

2. Don’t go out at night because it is very ………dangerous…… (DANGER)

3. This exercise is very ……difficult…….. I can’t do it. (DIFFICULTY)

4. Vietnam has a lot of …beautiful… beaches. (BEAUTY)

5. Air …pollution.. is a big problem in many cities in the world. (POLLUTE)

6. Our children sometimes go …camping..on the weekends. (CAMP)

7. I’m Vietnamese. What’s your …nationality.? (NATION)

8. Mount Everest is very high. It is the …highest.. mountain in the world. (HIGH)

9. I visit my grandparents ........once............. a month.( ONE)

10. We went to bed early because we had a ……tired….. day. (tire)

26 tháng 9 2023

\(2^n=\left(1000+24\right)\times1\)

\(2^n=1024\)

\(2^n=2^{10}\)

\(\Rightarrow n=10\)

15 tháng 5 2018

Do you know the subjects? What are their Vietnamese equivalents?

1. Art: ____Mỹ Thuật_____

2. English: _____Tiếng Anh________

3. Geography: _____Địa Lý________

4. History : ______Lịch Sử_________

5. Maths: ________Toán________

6. Music: ________Âm Nhạc__________

7. PE : _______Thể Dục__________

8. Science: _______Khoa Học__________

9. ICT :_______Công Nghệ________

16 tháng 5 2018

1. Mỹ thuât

2. Tiếng Anh

3. Địa lí

4. Lịch sử

5. Toán

6. Âm nhạc

7. Thể dục

8. Khoa học

9. Tin học

36/ noisy
37/ bakery
38/ teeth
39/ drives
40/ fifth

Fill in each numbered blank with one suitable word to complete the passage. Today is Sunday. .................(1) is fine and warm. Mr Minh's family are (2).................at home. They are working in the house now. Mr Minh is cleaning the doors and windows. Trung is helping (3)...................Mrs Nga and Thuy (4)...............in the kitchen. Mrs Nga is (5)....................... the dishes. Thuy is cleaning the vegetables. They are going to (6).................. a good lunch together....
Đọc tiếp

Fill in each numbered blank with one suitable word to complete the passage.

Today is Sunday. .................(1) is fine and warm. Mr Minh's family are (2).................at home. They are working in the house now. Mr Minh is cleaning the doors and windows. Trung is helping (3)...................Mrs Nga and Thuy (4)...............in the kitchen. Mrs Nga is (5)....................... the dishes. Thuy is cleaning the vegetables. They are going to (6).................. a good lunch together. Mr Minh's family are not free today. They are busy(7)....................the housework,but they are very happy. They are going to finish the housework at half past eleven, then (8)...................will have lunch. In the afternoon, they are going to the park. In the (9).................Trung and Thuy are going to (10).................... all their exercises before going to bed.

Answer: 1.................... 2....................... 3......................... 4......................... 5.............................. 6.................... 7....................... 8......................... 9.......................... 10..............................

2
16 tháng 12 2017

Fill in each numbered blank with one suitable word to complete the passage.

Today is Sunday ....it..... (1) is fine and warm. Mr Minh's family are (2).......staying.........at home. They are working in the house now. Mr Minh is cleaning the doors and windows. Trung is helping (3)........him...........Mrs Nga and Thuy (4)........are.......in the kitchen. Mrs Nga is (5).........washing.............. the dishes. Thuy is cleaning the vegetables. They are going to (6).......have.......... a good lunch together. Mr Minh's family are not free today. They are busy(7).......with.............the housework,but they are very happy. They are going to finish the housework at half past eleven, then (8)........they...........will have lunch. In the afternoon, they are going to the park. In the (9).......evening..........Trung and Thuy are going to (10).......do............. all their exercises before going to bed.

22 tháng 8 2023

Today is Sunday ....it..... (1) is fine and warm. Mr Minh's family are (2).......staying.........at home. They are working in the house now. Mr Minh is cleaning the doors and windows. Trung is helping (3)........him...........Mrs Nga and Thuy (4)........are.......in the kitchen. Mrs Nga is (5).........washing.............. the dishes. Thuy is cleaning the vegetables. They are going to (6).......have.......... a good lunch together. Mr Minh's family are not free today. They are busy(7).......with.............the housework,but they are very happy. They are going to finish the housework at half past eleven, then (8)........they...........will have lunch. In the afternoon, they are going to the park. In the (9).......evening..........Trung and Thuy are going to (10).......do............. all their exercises before going to bed.

3 tháng 5 2022

has

does your son get up 

Do your parents go 

is washing 

don't have

 

III. Read the passage and decide the sentences are True or False (5 x 0.2 = 1.0 pt):His sister’s name is Thuy Anh. She is a teacher of literature. She’s thirty - five years old. She is very, very beautiful. She is a teacher and round eyes. Her lips are quite full. Mrs. Thuy Anh has long black hair and a small nose. Her favorite food is fish, and her favorite drinks are orange juice and lemon juice.71. What does Mrs. Thuy Anh do?   -> …………… She is a teacher ………………………………………………72. Are her lips...
Đọc tiếp

III. Read the passage and decide the sentences are True or False (5 x 0.2 = 1.0 pt):
His sister’s name is Thuy Anh. She is a teacher of literature. She’s thirty - five years old. She is very, very beautiful. She is a teacher and round eyes. Her lips are quite full. Mrs. Thuy Anh has long black hair and a small nose. Her favorite food is fish, and her favorite drinks are orange juice and lemon juice.
71. What does Mrs. Thuy Anh do? 
  -> …………… She is a teacher ………………………………………………
72. Are her lips thin?   -> ………Yes, she is……………………………………………
73. Does she have a round face or an oval face?
  -> …………..……… She is a teacher ………………………………………
74. What color is her hair? 
    -> …………………She has long black hair………………………………………………
75. Does she like orange juice?
  -> ……………………Yes, she likes..………………………………………………

 

1
9 tháng 4 2022

ban làm r mà