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Triệu Vy
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hot boy 113
11 tháng 5 2018 lúc 20:21

bạn xem trong sách nâng cao phát triển ý, có nhiều bài khó lắm

Hoàng Thu Trang
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tiên
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Ngo Van Phuoc
15 tháng 5 2018 lúc 18:14

ban xem goole đấy có nhiều bài hay lắm

hoàng ngọc ánh
15 tháng 5 2018 lúc 18:22

bn cứ lên google nhé có nhiều lắm

wendy nguyễn
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Mina
24 tháng 7 2018 lúc 20:52

 NHÂN CÁC ĐA THỨC

1. Tính giá trị:

B = x15 - 8x14 + 8x13 - 8x2 + ... - 8x2 + 8x – 5 với x = 7

2. Cho ba số tự nhiên liên tiếp. Tích của hai số đầu nhỏ hơn tích của hai số sau là 50. Hỏi đã cho ba số nào?

3. Chứng minh rằng nếu: thì (x2 + y2 + z2) (a2 + b2 + c2) = (ax + by + cz)2

CÁC HẰNG ĐẲNG THỨC ĐÁNG NHỚ

1. Rút gọn các biểu thức sau:

a. A = 1002 - 992+ 982 - 972 + ... + 22 - 12

b. B = 3(22 + 1) (24 + 1) ... (264 + 1) + 12

c. C = (a + b + c)2 + (a + b - c)2 - 2(a + b)2

2. Chứng minh rằng:

a. a3 + b3 = (a + b)3 - 3ab (a + b)

b. a3 + b3 + c3 - 3abc = (a + b + c) (a2 + b2 c2 - ab - bc - ca)

Suy ra các kết quả:

i. Nếu a3 + b3 + c3 = 3abc thì a + b + c = 0 hoặc a = b = c

Bài tập toán nâng cao lớp 8

3. Tìm giá trị nhỏ nhất của các biểu thức

a. A = 4x2 + 4x + 11

b. B = (x - 1) (x + 2) (x + 3) (x + 6)

c. C = x2 - 2x + y2 - 4y + 7

4. Tìm giá trị lớn nhất của các biểu thức

a. A = 5 - 8x - x2

b. B = 5 - x2 + 2x - 4y2 - 4y

5. a. Cho a2 + b2 + c2 = ab + bc + ca chứng minh rằng a = b = c

b. Tìm a, b, c biết a2 - 2a + b2 + 4b + 4c2 - 4c + 6 = 0

6. Chứng minh rằng:

a. x2 + xy + y2 + 1 > 0 với mọi x, y

b. x2 + 4y2 + z2 - 2x - 6z + 8y + 15 > 0 Với mọi x, y, z

7. Chứng minh rằng:

x2 + 5y2 + 2x - 4xy - 10y + 14 > 0 với mọi x, y.

8. Tổng ba số bằng 9, tổng bình phương của chúng bằng 53. Tính tổng các tích của hai số trong ba số ấy.

9. Chứng minh tổng các lập phương của ba số nguyên liên tiếp thì chia hết cho 9.

10. Rút gọn biểu thức:

A = (3 + 1) (32 + 1) (34 + 1) ... (364 + 1)

11. a. Chứng minh rằng nếu mỗi số trong hai số nguyên là tổng các bình phương của hai số nguyên nào đó thì tích của chúng có thể viết dưới dạng tổng hai bình phương.

b. Chứng minh rằng tổng các bình phương của k số nguyên liên tiếp (k = 3, 4, 5) không là số chính phương.

PHÂN TÍCH ĐA THỨC THÀNH NHÂN TỬ

1. Phân tích đa thức thành nhân tử:

a. x2 - x - 6

b. x4 + 4x2 - 5

c. x3 - 19x - 30

2. Phân tích thành nhân tử:

a. A = ab(a - b) + b(b - c) + ca(c - a)

b. B = a(b2 - c2) + b(c2 - a2) + c(a2 - b2)

c. C = (a + b + c)3 - a3 - b3 - c3

3. Phân tích thành nhân tử:

a. (1 + x2)2 - 4x (1 - x2)

b. (x2 - 8)2 + 36

c. 81x4 + 4

d. x5 + x + 1

4. a. Chứng minh rằng: n5 - 5n3 + 4n chia hết cho 120 với mọi số nguyên n.

b. Chứng minh rằng: n3 - 3n2 - n + 3 chia hết cho 48 với mọi số lẻ n.

5. Phân tích các đa thức sau đây thành nhân tử

1. a3 - 7a - 6

2. a3 + 4a2 - 7a - 10

3. a(b + c)2 + b(c + a)2 + c(a + b)2 - 4abc

4. (a2 + a)2 + 4(a2 + a) - 12

5. (x2 + x + 1) (x2 + x + 2) - 12

6. x8 + x + 1

7. x10 + x5 + 1

6. Chứng minh rằng với mọi số tự nhiên lẻ n:

1. n2 + 4n + 8 chia hết cho 8

2. n3 + 3n2 - n - 3 chia hết cho 48

7. Tìm tất cả các số tự nhiên n để:

1. n4 + 4 là số nguyên tố

2. n1994 + n1993 + 1 là số nguyên tố

8. Tìm nghiệm nguyên của phương trình:

1. x + y = xy

2. p(x + y) = xy với p nguyên tố

3. 5xy - 2y2 - 2x2 + 2 = 0

wendy nguyễn
1 tháng 8 2018 lúc 8:07

giả dùm câu 1 phần các hằng đẳng thức đáng nhớ

Nguyễn Thị Ngọc Mai
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Nguyễn Thị Ánh Thy
24 tháng 3 2018 lúc 18:00

Mình ko có

Xin lỗi mình lớp 5

nguyen thi khanh huyen
1 tháng 5 2018 lúc 9:36

tuấn sau nữa thi xong tui cho.

♡LT BảoTrân♡
12 tháng 5 2022 lúc 9:12

Ơ mink cũng đang có nek mà khổ nỗi mink lại có mẹ làm giáo viên ko cho chia sẽ các đề có thể có trong thi hsg. Cậu có lấy đề ôn đc ko?

nam tran
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Võ Thị Giang
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Phương Nguyễn
17 tháng 2 2016 lúc 17:26

mink có đề thi ! bạn lấy ko ?Hỏi đáp Ngoại ngữ Hỏi đáp Ngoại ngữ

Mai Nhật Lệ
17 tháng 2 2016 lúc 19:28

Unit 1 - MY NEW SCHOOL

I. Find the word which has a different sound in part underlined.
 

1/

A. funny

B. lunch

C. sun

D. computer

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

II. Match one word in A with one in B.

AB
dobasketball
playa school uniform
studyhomework
ridevocabulary
weara bicycle


III. Write positive and nagative sentences with the present simple or the present continuous.
Examples:
- Hoa / ride to school / every day (+) 
 Hoa rides to school every day.
- They / have breakfast / now (-)
 They are not having breakfast now.

1/ My friends / go to school by bus. (-)
2/ The library / open at 7:30 AM. (+)
3/ Students / have a break / right now. (-)
4/ I / study English / at the moment. (+)
5/ Look! Our parents / wait outside. (+)

IV. Choose the best option (A, B or C) to each space. 
1. Every morning, I always ...... to school at 6.30 and ...... home at about 11:30. 

A. go; come

B. goes; comes

C. go; comes

2. While I ...... at school, my Mum ...... to the market.

A. study; go

B. am studying; is going

C. study; is going

3. At break time, I ...... to the library and ...... books.

A. read; go

B. goes; reads

C. go; read

4. I usually ...... to school by bike, and my mother ...... to work by motorbike.

A. go; go

B. goes; goes

C. go; goes

5. When I ...... books, I always ...... very happy.

A. read; feel

B. reads; feel

C. reads; feels

V. Find one odd word A, B, C or D. Then read them aloud.
 

1/

A. cantten

B. library

C. classroom

D. bedroom

2/

A. studying

B. singing

C. morning

D. listening

3/

A. father

B. nurse

C. engineer

D. teacher

4/

A. notebook

B. compass

C. basketball

D. schoolbag

5/

A. maths

B. Viet Nam

C. geography

D. English

VI. Put the verbs in brakets in the correct tense form.
1. School (finish) ......... at 4.30 p.m every day.
2. Listen! ......... they (sing) ......... in the classroom?
3. - Where ......... you (be) ......... , Phong?
    - I'm upstairs. I (do) ......... my homework.
4. My family like (spend) ......... our summer holidays at the seaside.
5. It's warm today. I (not want) ......... (stay) ......... at home now. What about (go) ......... swimming in the river?
6. ......... you often (eat) ......... lunch in the school canteen?
VII. Put a word from the box in each space to complete the following passage.
 

library    work    students    schoolyard    name    
love    break    beautiful    understand    forty


The ......... of my school is Luong The Vinh Secondary school. It is a ......... school. There are about eight hundred ......... and more than  ......... teachers in my school. They ......... very hard so that we can ......... the lessons well. My school’s ......... is very big. You can see all kinds of books in it. We also have a very large and clean .......... Students play all kinds of games during their ......... time. My school is not big, but I ......... it very much.

VIII. Read the passage and then choose the best answer. 

   My name is Quang. I am in class 6A1 at Nguyen Du School. It is a small school on Nguyen Du street. My classroom is on the second floor. There are 40 students in my class. My form teacher is Miss Mai. She teaches us English. All of my classmates are really kind and hard-working. We always finish all homework at home. Every day, we start classes at seven o’clock and have a 20-minute break at thirty-five past eight. My school has a small schoolyard so the students usually stay in class or sit in the canteen at break time. After that, we are back to our room and finish class at half past eleven.

Choose the best answer:
1. Which floor is Quang's classroom in?

A. The first floor

B. The second floor

C. The third floor

2. What subject does Quang's form teacher teach?

A. English

B. Math

C. Literature

3. What is NOT true?

A. Quang's in grade 6

B. Quang's classmate are all nice

C. Quang's school is big

4. What time does Quang have break time?

A. At 8.30

B. At 8.35

C. At 8.20

5. What do the students usually do at break time?

A. Sit in the canteen

B. Stay in class

C. A and B


IX. Read the conversation and answer the questions.
Mr Green:  Hey, Tom. How’s your first week at the new school?
Tom:  It’s great. But I was a bit nervous at first.
Mr Green:  Why were you nervous?
Tom:  The teachers are all new to me, most of my classmate are new too.
Mr Green:  Are they friendly to you?
Tom:  Ah, yeah. They are all nice to me.
Mr Green:  What subjects did you have today?
Tom:  Well, we had maths, geography and computer studies, my favourite subject.
Mr Green:  Oh, good. So everything is going well at school?
Tom:  Right. I had a good first day. And… Dad, can I join the judo club at school? I like   to do judo.
Mr Green:  Yeah, Ok, if you like. But don’t forget to do your homework.
Tom:  I won’t. Thanks, Dad.

Questions:
1. Why was Tom nervous at first?
2. What are Tom's teacher and friends like?
3. What is his favourite subject?
4. What club does he want to join?
5. Is Tom having a nice first week at his new school?

X. Choose the correct word A, B and C for each of the gaps to complete the following text.
  What do you do if you want to ...(1)... a book in a library? If you know the author's ...(2)..., go to the author catalogue. Find the title of the book ...(3)... check the shelf mark. Make a note of this before you look ...(4)... the appropriate shelf. If you do not know the author's name, go to the ...(5)... catalogue. If there ...(6)... no title catalogue in the library, go to the subject catalogue. Check all the titles which are under the ...(7)... you want. Then check the appropriate card, as with the author catalogue. Next look for the book on the shelf. Let the librarian stamp it ...(8)... you take it out of the library. If the book isn't on the shelf, ask the librarian to get it for you.
 

1/

A. find

B. look

C. take

2/

A. address

B. title

C. name

3/

A. and

B. or

C. but

4/

A. at

B. after

C. for

5/

A. title

B. author

C. subject

6/

A. be

B. are

C. is

7/

A. subject

B. book

C. index

8/

A. after

B. before

C. when

Mai Nhật Lệ
17 tháng 2 2016 lúc 19:29

Unit 2 - MY HOME

I. Find the word which has a different sound in part underlined.
 

1/

A. maps

B. clothes

C. clock

2/

A. rooms

B. vases

C. watches

3/

A. hotels

B. rooms

C. apartments

4/

A. flowers

B. trees

C. plants

5/

A. dishes

B. chopsticks

C. cups

II. Find one odd word A, B, C or D. Then read them aloud.
 

1/

A. cousin

B. uncle

C. niece

D. principle

2/

A. bedroom

B. toilet

C. library

D. kitchen

3/

A. cook

B. television

C. fridge

D. cooker

4/

A. calculator

B. pillow

C. blanket

D. bed

5/

A. apartment

B. park

C. villa

D. slit house

6/

A. sofa

B. chair

C. toilet

D. table

7/

A. cooker

B. desk

C. dishwasher

D. fridge

8/

A. bed

B. lamp

C. fan

D. villa

9/

A. aunt

B. uncle

C. grandmother

D. teacher

10/

A. cousin

B. mother

C. father

D. brother

III. Complete each sentence so it means the same as the sentences above.
1. I don't have a bookshelf in my bedroom.
 There ......
2. We have a sink, a fridge, a cooker and a cupboard in our kitchen.
 There ......
3. The notebook is on the book.
 The book ......
4. The dog is in front of the microwave.
 The microwave ......
5. My favourite room in the house is the living room.
 I like ......
IV. Fill each blank in the following passage with a suitable word from the box.
   untidy      are      not      near      next      on      his      bag  An's bedroom is big but messy. There ...(1)... clothes on the floor. There is a big desk ...(2)... the window, there are dirty bowls and chopsticks ...(3)... it. He usually puts his school ...(4)... under the desk. His bed is ...(5)... to the desk, and it is also ...(6).... There is a cap, some CDs and some books on the bed. An's Mum is ...(7)... happy with this, and how An is tidying up ...(8)... room.

V. Read the passage and choose the best word (A, B or C) to put in each space.
  I am a ...(1)... in a house. Every day, members in the family take a ...(2)... in me. They brush their teeth, wash their ...(3)..., and ...(4)... dressed every morning. I usually get wet on my floor. Who I am? I am a ...(5)....
 

1/

A. corner

B. box

C. room

2/

A. break

B. bath

C. rest

3

A. eyes

B. faces

C. teeth

4/

A. put

B. take

C. get

5/

A. bedroom

B. kitchen

C. bathroom


VI. Read the email and choose the best answer (A, B or C) to each question.

     From: nhipham@hotmail.com
     To: peter@coldmail.com
     Subject: Summer Trip

Dear Peter,
We are having a great summer trip in Da Lat. This is a nice city. The weather is cool in the morning and quite cold at night. I really love this kind of weather. We rent a villa istead of staying in a hotel. It is big and a little bit scary because there are just few people here. The view, however, is totally wonderful. There is a small garden with roses and i love it a lot. Wish you were here with us. You will love it for sure. We will go back to Ho Chi Minh City tomorrow. I will miss Da Lat so much. How about your summer, peter? I hope to hear from you soon.
From Viet Nam with love,
Nhi Pham1. What season is it?

A. Spring

B. Summer

C. Fall

2. What is the weather like?

A. Hot in the morning - cold at night

B. Cold in the morning - hot at night

C. Cool in the morning - cold at night

3. What is NOT TRUE about the letter?

A. Nhi's family is staying in a hotel

B. Nhi loves the weather in Da Lat so much

C. Da Lat is a beautiful city

4. Why is the villa scary?

A. Because it is big

B. Because the weather is really cold

C. Because not many people live here

5. Who is Nhi writting to?

A. Nhi's sister

B. Nhi's friend

C. Nhi's father

VII. Choose the correct word A, B or C to fill each blank in the following conversation.
Mum: We are moving to the new apartment next month. Do you want to have a new bed?
Mi: No, I don’t, Mum. I ……(1)…… my old bed. It’s so comfortable. But can I ……(2)…… a new poster?
Mum: You have three posters already. You can put them ……(3)…… the wall in your new room.
Mi: Yes, Mum. I want to have a family photo on my desk. There ……(4)…… only a lamp on it now. 
Mum: That’s a good idea. Oh, where do you want to put your desk?
Mi: ……(5)…… to my bed, Mum. I also want a small plant in my room.
Mum: That’s fine. It can go ……(6)…… the bookshelf and the desk.

Hoàng Thị Minh Phương
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Đỗ Thị Ngọc Trinh
23 tháng 1 2016 lúc 10:58

ko

Phạm Phương Anh
23 tháng 1 2016 lúc 11:08

ko

Quỷ Khát Máu
23 tháng 1 2016 lúc 15:33

mk cos di thi muon de ak bao mk mk cho okChưa phân loại

Hoàng Nguyên Ngọc Bình
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