=> \(\left(-\frac{1}{7}\right)^{n-\left(n-2\right)}=\left(-\frac{1}{7}\right)^{n-n+2}=\left(-\frac{1}{7}\right)^2=\frac{1}{49}\)

Ta có: 23a + 23b chia hết cho 23  

=> 7a + 3b + 16a + 20b chia hết cho 23  

=> 7a + 3b + 4(4a + 5b) chia hết cho 23  

Do 7a + 3b chia hết cho 23 nên 4(4a + 5b) chia hết cho 23  

Mà 4 không chia hết cho 23 nên 4a + 5b phải chia hết cho 23

It's important to (1).......eat............. well, especially when you are studying. If you are at primary (2)......school .................., you may not go home for lunch and have a cooked meal of meat or (3)...........fish............ and vegetables. A chicken and lettuce sanwich, with some (4).............fresh.................. fruit would be a light but (5).................. healthy............... lunch. Many people around the world eat plain, boiled (6)..............rice .............. two or three times a day.

Pulpils and students often don't eat (7)............ well.................. when they're revising for an exam - they eat chocolate and (8).............drink.................. lots of black coffee! And by the wat, doctors say everybody should starts the day with healthy (9)............ breakfast.................... It's also good for you to drink a lot of (10)............water.............. through the day.

*Answer the following question:

1. Is eating well important? yes, it is

2. What won't it happen when you are at primary school?

If you are at primary school, you may not go home for lunch and have a cooked meal of meat or fish. and vegetables.

3. What would be a healthy lunch?

A chicken and lettuce sanwich, with some fresh fruit would be a healthy lunch.

4. Do pupils and students eat well when they are revising for an exam?

no, they don;t

5. What should the doctor give you advice?

doctors say everybody should start the day with healthy breakfast

\(\frac{2x+1}{5}=\frac{3y-2}{7}=\frac{2x+3y-1}{6x}\)

Áp dụng tính chất dãy tỉ số bằng nhau, ta có:

\(\frac{2x+1}{5}=\frac{3y-2}{7}=\frac{2x+3y-1}{6x}=\frac{2x+1+3y-2}{5+7}=\frac{2x+3y-1}{12}\)

=> \(\frac{2x+3y-1}{6x}=\frac{2x+3y-1}{12}\)

=> 6x = 12

=> x = 2

Thay x = 2 vào \(\frac{2x+1}{5}\), ta có:

\(\frac{2.2+1}{5}=\frac{3y-2}{7}=1\)

=> 3y - 2 = 7

=> 3y = 9

=> y = 3

=> x + y = 2 + 3 = 5

KL: x + y = 5

1. Khoanh vào đáp án đúng:

1. Did your counry ................. a water fastival last year?

a. hold b. held c. holds d. holding

2. There .............. a lot of foreigners at Hue fastival last summer.

a. is b. are c. was d. were

3. he is a worker and he is ...................... in a big factory.

a. works b. does c. working d. doing

2. Đọc bài văn sau điền T hoặc F.

Teacher: Keep silent, everydaybody! This is Trang, new member of our class. She was born on May 26th, 2000 in Vinh Phuc province. She likes watching TV and listening to music. In freetimes, she often helps her parents do housework. Her favourite subject is English and her favourite sport is badminton. She wants to be an English teacher in the future. I hope you all will have happy time together.

1. Trang is the old member of the 5a. F

2. Teacher was born on May 26th. F

3. Trang likes listening to music. T

4. Trang likes badminton and she wants to be a good badminton player. F

5. She likes to be an English teacher in the future. T

I. Choose the most suitable word or phrase to fìll in the blank.

1. Davis has a good ___________of humor.

a. scene b. scent c. sense d. cent

2. I don’t have enough money ___________.

a. for a holiday b. to go a holiday c. going on holiday d. to a holiday

3. In Britain, school always___________ in September.

a. begin b. begins c. began d. beginning

4. Her new glasses change her ___________.

a. appear b. appears c. appearances d. appearance

5. Surely 15 minutes is enough time ___________.

a. for you to have a bath b. to you for having a bath

c. to you to have a bath d. for you for having a bath

6. He wasn’t ___________the job.

a. experienced enough to b. enough experienced to

c. experienced enough for d. enough experienced for

7. Is there enough room ___________in the car?

a. to me b. for me c. for I d. to I

8. It was generous___________ you to share your food with me.

a. about b. to c. for d. of

9. Reading books ___________one of my hobbies.

a. be b. is c. are d. will be

10. Tim enjoys___________ to the zoowith his friends at the weekends.

a. go b. goes c. going d. to go

11. What do you often do ___________Christmas?

a. at b. in c. for d. on

12. It ___________Hoa 25 hours a week ___________ her homework.

a. takes/ do b. take/ to do c. takes/ to do d. took/ doing

II. Choose the words or phrases that need correcting.

1. Many foreigners will=> bỏ will come to visit Viet Nam every year.

A B C D .............................................................................

2. Mary has an important exam so she works very hardly.=> hard

A B C D .............................................................................

III. Use the correct word form of the word given in each sentence.

1. Nam, you look ____happily_______ today? (HAPPYLY)

2. His stories are full of ____humor_______. (HUMOROUS)

3. I likethe _____peace______ and quiet of the country. (PEACEFUL)

4. They are _____lucky______ enough to escape______punishment_____. (LUCK/ PUNISH)

5. He was an orphan so he had to spend his childhood in an orphanage. (CHILD / ORPHAN)

6. Ba is a ______funny_____boy. He has got a ______humorous _____sense. (FUN / HUMOR)

7. Nhan is always ______helpful_____to his mother. (HELP)

8. Marconi was the_____inventor______ of the radio. (INVENT)

IV. Supply the correct forms of verbs in brackets.

Nam (1. enjoy) _____enjoys______ (2. climb) _____climbing ______ mountains. He (3. go) ____goes climbing _______ (4. climb) ___________ whenever he (5. have) _______has____ time. Most of the time he (6. climb) _______climbs____with his best friend, Nien.

Last Friday (7. be) ____was_______a public holiday. They (8. decide) ____decided_______ (9. climb) _______to climb____ Chau Thoi mountain.

“We (10. return) _will return________before dark”, they (11. tell) _____told ______ theirparents before they (12. set) ____set_______off.

It (13. take) ____took_______them for 4 hours (14. climb) ______to climb_____ up to thetop of the mountain. (15. stand) _____standing ______ from that height, they (16. can) ___could ________ see the whole village below. What a marvelous sight!

V. Read the passage carefully. Then decide whether each of the following statements is TRUE or FALSE.

All of my friends, I like Amanda best or she is my best friends. She is a pretty girl with bright eyes, smooth skin, delicate lips and a quick clever mind, making her so remarkable not only in the class but also at school. She does so well in studying that our teachers often take her as an example for us. Amanda has many hobbies, but she likes singing and acting best. Sometimes she is chosen to act in some school plays. Amanda and I have many things in common. I love the things she loves. She hates the things I hate. What a wonderful friendship we have!

1. Amanda looks nice and intelligent. ..........................T...................................................

2. Amanda is popular only in the class. .................................F............................................

3. Amanda is an excellent student. ................................T.............................................

4. Amanda likes taking part in school plays. .............................T................................................

5. Talking about hobbies, Amanda and I don’t share anything. ..................F...........................................................

VI. Read the following passage and then answer the question.

My name’s Ellen and my husband's name is Peter. We’ve got three children - two sons and a daughter. Our sons’ names are Ian and Ben. They’re twins, but they are not identical (giống hệt). Ian has got dark hair, but Ben’s hair is fair. Our daughter’s name is Tracy. She is eight years old. The boys are four.

1. How many people are there in Ellen’s family? ......................THERE ARE FIVE PEOPLE IN ELLEN'S FAMILY.......................................................

2. How many children do they have? ................THEY HAVE 3 CHILDREN .............................................................

3. What do their sons look like? .........................They’re twins, but they are not identical ....................................................

4. How old is Ben? ...............................HE IS FOUR YEARS OLD..............................................

5. What is the name of Ellen’s daughter? ......................HER NAME IS TRACY.......................................................

VII. Rewrite each sentence, beginning as shown so that the meaning stays the same.

1. Mary can't go to school because she is too young.

Mary isn’t .......................OLD ENOUGH TO GO TO SCHOOL..........................................................................................................................................................................

2. Are you very tall? Can you reach that picture?

Are you tall ......................ENOUGH TO REACH THAT PICTURE.......................................................................................................................................................................

3. There are ten people in the room but there are only eight chairs.

There aren’t ..............................ENOUGH CHAIRS FOR TEN PEOPLE IN THE ROOM.............................................................................................................................................................

4. This picture is 9.50 so I can’t buy it.

I don’t have ......................ENOUGH MONEY TO BUY THIS PICTURE.......................................................................................................................................................................

5. How much is that shirt?

How much does ......................HAT SHIRT COST ?.............................................................................................................................................................

6. Let’s go out tonight.

Shall we.................GO OUT TONIGHT ?.....................................................................................................................................................................................

7. His hobby is to collect stamp.

He enjoys ......................COLLACTING STAMPS...........................................................................................................................................................................

8. Lan spends three hours a day doing her homework.

It takes ......................LAM 3 HOURS A DAY TO DO HER HOMEWORK.................................................................................................................................................................................

CPMPLETE THE SENTENCES USING THE PRESENT SIMPLE OF THE VERBS

1.....Does this film begin.......(this film/ begin)at 3.30 or 4.30

2. the art exhibition...opens..(open) on 3 May and..ends...(end) on 15 July

3. the train..leaves...(leave) Plymouth at 11.30 and...arrives..(arrive) in London at 14.45

4. we..starts..(start) out work on Monday and..finishes..(finish) on Friday

5. i'm bored with this TV program. when..does it finish...(it/ finish)?

6. "what time..does your train leave ..(your train/leave) tomorow?"

" 7 o'clock in the morning, it...gets.(get) into Paris at 11

7. next Friday...is .(be) thirteenth

8." where ..do they collect ....( they/collect) garbage?" at Dong Xuan market"

9. " what time.do you finish..(you/ finish) your work tomorrow?

10. my train..leaves..(leave)at 11.30, so i need ...to be ..(be) at the station by 11.15

Make questions
Example:
A: Will you be at home tomorrow night ?
B: Yes,I will . ( I'll be at home tomorrow night )

1.A:_____WILL THE PLANE BE ON TIME ?_____
B: Yes,___IT WILL___. ( the plane will be on time )
2.A:_____WILL THE DINNER BE READY IN A FEW MINUTES ?_____
B:Yes,______IT WILL__( Dinner will be ready in a few minutes )
3.A:_____ WHEN WILL THE DINNER BE READY ?_____
B:In a few minutes. ( Dinner will be ready in a few minutes )
4.A:______WHEN WILL YOU GRADUATE ?____
B: Next year. ( I'll graduate next year )
5.A:___WHERE WILL MARY GO TO SCHOOL ? _______
B: At the community college. ( Mary will go to school at the community next year )
6.A:_____wILL JANE AND MẢKR BE AT THE PARTY_____
B: No,__THEY WON'T_____ ( Jane and Mark won't be at the party )
7.A:_____WILL MIKE ARRIVE IN CHICAGO NEXT WEEK ?_____
B:Yes,_____SHE WILL__ ( Mike will arrive in Chicago next week
8.A:____WHERE WILL MIKE BE IN ?______
B: In Chicago. ( Mike will be in Chicago next week )
9.A:____WILL YOU BE AT HOME EARLY TONIGHT ?______
B: No,___I WON'T____ ( I won't be at home early tonight )
10.A:____WHEN WILL DR SMITH BE BACK ?______
B: In a few minutes. ( Dr Smith will be back in a few minutes )
11.A:____WILL YOU BE RADY TO LEAVE AT 8: 15 ?______
B: Yes,___I WILL___ ( I'll be ready to leave at 8:15 )
A: Are you sure ?