Trong một đề thi có 3 câu: Một câu về số học, một câu giải tích, một câu về hình học. Trong 60 học sinh dự thi, có 48 học sinh giải được câu số học, 40 học sinh giải được câu giải tích, 32 thí sinh giải được câu hình học. Có 57 thì sinh giải được câu số học hoặc giải tích, 50 học sinh giải được câu giải tích hoặc hình học, 25 thí sinh giải được câu số học hoặc hình học, 15 thí sinh giải được 3 câu, Hỏi có bao nhiêu thí sinh không giải được câu nào ? 

Tìm tất cả các cặp số nguyên (x, y) thỏa mãn: x(x² - y) + (y - 3)(x² + 1) = 0

Ở 50oC, độ tan của KCl là 42,6g. Nếu cho 120g KCl vào 250g nước thì dung dịch thu được là bão hòa hay chưa bão hòa. Tính khối lượng KCl không tan hay cho thêm vào để được dung dịch bão hòa ở nhiệt độ trên

1) chứng minh A = 1 + 19¹⁹ + 93¹⁹⁹ + 1993¹⁹⁹⁴ không phải là số chính phương ?

1 phần 3 giờ bằng mấy phút 

Phân tích các đa thức sau thành nhân tử:
a) 5x²y- 10xy²        b) x²  + 2xy + y² - 5x - 5y      
c) x² – 6x + 8          d)5x² – 10xy + 5y² – 20z²

Một phương pháp được đề xuất để loại bỏ SO₂ khỏi khí thải của nhà máy điện bằng cách dẫn khí thải qua dung dịch H₂S.

(a) Viết phương trình phản ứng giữa SO₂ và H₂S.

(b) Cần bao nhiêu lít H₂S (ở đkc) để loại bỏ SO₂ sinh ra khi đốt cháy 2,0 tấn than chứa sulfur chiếm 3,5% theo khối lượng? Biết các phản ứng xảy ra hoàn toàn.

Ở độ cao 10km cách mặt đất thì áp suất không khí là 30,6kPa nhiệt độ 230K. Tính khối lượng riêng và mật độ phân tử của khí ở độ cao đó. Cho khối lượng mol không khí là 28,8kg/mol

Một đội 24 người trồng xong số cây dự định trong 5 ngày. Nếu đội được bổ sung thêm 6 người nữa thì sẽ trồng xong số cây ấy sớm được mấy ngày (giả sử năng suất làm việc của mỗi người là như nhau)?

tại sao khi phân huỷ KMnO4 ta phải đặt nghiêng ống nghiệm

các từ có cùng nghĩa với "dũng cảm"

Tại sao có trường hợp NaOH tác dụng với khí SO2 lại tạo ra 2 muối là Na2SO3 và NaHSO3

Cho x +y = 1. Tính P = x³ - y³ - 3xy

10000:100=?

Thực hiện  phép tính:

x(1 - x) + (x - 1)²

12 x 35 + 35 x 182 - 35 x 94

một cửa hàng bán một cái tủ lạnh giá 4.500.000 đồng thấy lãi 10% giá bán. Tính giá mua chiếc tủ lạnh

700:8 bằng bao nhiêu

Hãy kể tên các khu vực của châu Á? Việt Nam thuộc khu vực nào? 

Rút gọn  biểu thức:

B=3+3²+3³+...+3¹⁰⁰

Bài 60: Dùng pa-lăng gồm 1 ròng rọc động, 1 ròng rọc cổ định để đưa một vật có khối lượng 60 kg lên cao thì phải kéo dây đi một đoạn là 2 m.a) Bỏ qua lực ma sát và rọng lượng các ròng rọc, tìm độ lớn lực kéo? Quãng đường vật di chuyển ? Công của lự...

WORD FORM 1

The ao dai is the _____ dress of Vietnamese women. TRADITION
Tet holiday is the most important _____ for Vietnamese people. CELEBRATE
We have to be _____ when riding our bikes on the streets. CARE
The old man walked _____ to the park. SLOW
The author's _____ is communicated through his song. HAPPY
We find Huong very _____. COMMUNICATE
They went to see most of the __________places. INTEREST
His sudden _____ must be a shock to her and her family. DIE
The other _____ admired him. COMPLETE
We can only get their by plane. There is no _____. CHOOSE
WORD FORM 2

Sony is a big firm which is _____ in Vietnamese's market. COMPETE
Doctors and _____ have reported on how we are all affected by the noise around us. SCIENCE
The _____ between Vietnam and China is recovered. FRIEND
The boss refused to meet the Union's _____. DELEGATE
Many _____ activities will be held tomorrow. CULTURE
She _____ with me for an hour about the future job yesterday. REASON
The _____ of the moon for the earth causes the tides. ATTRACT
Our team played _____. We lost. SUCCESS
It is said that Hue is a _____ city. PEACE
He came first in the _____. COMPETE
WORD FORM 3

Good _____were the keys to the success of the 23th Sea Games. PREPARE
We are _____ interested in AIDS. ESPECIAL
Women have to keep their _____. GENTLE
We all have our _____. WEAK
His _____ makes him jobless. SHY
Your answer is _____ right. EXACT
Everyone admires her _____ to help the poor. READY
Dick becomes _____ because of his laziness. JOB
I put my book near the desk for _____. CONVENIENT
She has one of the biggest stamp _____ in Britain. COLLECT
WORD FORM 4

The gas from the chemical factory was extremely _____. HARM
D. E. Huges was the _____ of microphone. INVENT
There are a lot of _____festivals in Vietnam. TRADITION
They work hard in order to _____ good crops from poor soil. PRODUCT
I hope there won,t be too much _____ in getting a work permission. DIFFICULT
The children are more _____ in cartoon. INTERST
Many tourists have been attracted by the _____ of Ha Long Bay. BEAUTIFUL
Designers have _____ the ao dai for ages. MODERN
She divorced him because of his _____ to the children. KIND
They love Thanh Lam because of her _____ voice. BEAUTY
WORD FORM 5

His _____ made him jump out of his seat. EXCITE
I like him because he always talks to his parents _____. POLITE
Many _____ choose to go to this part of the seaside. SWIM
Those boys and girls were _____ by the performance of the clown. FASCINATE
Money can't buy _____. HAPPY
Islam is one of the great world _____. RELIGIOUS
He learns very well and his parents are very _____ of him. PRIDE
They hate being _____ on their parents. DEPEND
If you want to attend the course, you must pass the _____ examination. WRITE
The weather was fine yesterday. It was _____ and sunny. CLOUD
WORD FORM 6

Polluted water can _____ do harm to people's health. DIRECT
She broke the vase because of her _____. CARE
I think English is an _____ subject. IMPORTANCE
Trinh Cong Son is one of the most well-known _____ in Vietnam. MUSIC
Many people enjoy the pleasure and _____ of living downtown. COVENIENT
It is a _____ to meet you. PLEASE
He wants to make a good _____ on everyone he meets. IMPRESS
It is my great _____ to meet you at this important meeting. PLEASE
There were two _____ between the two programs. DIFFER
There are many _____ programs at the Festival in Hue. CULTURE
WORD FORM 7

That _____ has composed a lot of beautiful songs. MUSIC
Lucy got _____ quickly and went for work. DRESS
He drives so _____ that he often has accidents. CARE
The computer is one of the most marvelous _____ in our modern age. INVENT
Housework has _____ been regarded as women's work. TRADITION
You must write your _____ form clearly. APPLY
He was very _____ of the work he had done. PRIDE
The children are playing _____ on the beach. HAPPY
The children are more _____ in cartoons. INTEREST
We started our trip on a beautiful _____ morning. SUN
WORD FORM 8

You have to keep your _____ from that snake. DISTANT
They are _____ greeted by the native. WARM
The _____ by the little girl was a great hit. PERFORM
Some young people today have a very strange _____. APPEAR
You don't have to do that work. In other words, it's _____ for you. NECESSITY
Although she is rich, she lives _____. UNHAPPY
They went to see most of the _____ places. INTEREST
Air _____ makes us unhealthy. POLLUTE
They have made careful _____ for the demonstration. PREPARE
We all looked _____ after the summer holiday. HEALTH
WORD FORM 9

I find that this magazine is very _____. INFORM
It was an _____ day. ENJOY
Thanks to television, people can get the latest _____ around the world quickly. INFORM
The Internet has _____ developed and became part of our daily life. INCREASE
Because of his _____ driving, she caused an accident. CARE
In recent years, there has been many _____ in science. DEVELOP
The plane arrived _____ after a violent storm. SAFE
_____ air does a lot of harm to our life. POLLUTE
I had a good _____ on this film. IMPRESS
His result was _____ excellent. AMAZE
WORD FORM 10

Wearing casual clothes helps students have freedom of _____. CHOOSE
Telephone is one of the greatest _____ in 19th century. INVENT
Van Cao is one of the most famous _____ in Vietnam. MUSIC
I think the Internet is a _____ device to get information. USE
I sent her a letter last month but I have received no _____ from her. RESPOND
Food and clothing are _____ of life. NECESSARY
She can find no _____ to her financial troubles. SOLVE
All _____ to Washington are delayed because of the bad weather. FLY
The _____ of their house left them no place to live. DESTROY
We all looked _____ after the summer holidays. HEALTH
WORD FORM 11

The _____ of people prefer TV to radio. MAJOR
The next stage in the _____ of television is interactive TV. DEVELOP
The country,s official _____ of Malaysia is Islam. RELIGIOUS
I like this website because it is _____ for me. USE
I hope to speak English as _____ as my teacher. GOOD
The _____ of the new guest caused trouble to my aunt. ARRIVE
He learns very well and his parents are _____ of him. PRIDE
Many _____ have made lots of changes to The ao dai. DESIGN
Thousands of people have been made _____ by the flood. HOME
She was _____ because her mother was sick. HAPPY
WORD FORM 12

We take _____ in being students of one of the most famous schools in this city. PROUD
What is the _____ between the ao dai nowadays and the one 100 years ago? DIFFERENT
The government has plans to _____ this city. MODERN
Those boys are _____ to talk to. INTEREST
The earthquake in Kobe in 1995 caused _____ damage. DISASTER
_____, people eat sticky rice cakes at Tet. TRADITION
He is an _____ of this newspaper. EDITION
This book is not _____. AVAIL
It's an _____ day. ENJOY
He _____ answered these questions. EXACT

Hai bể chứa được 2700l dầu.Nếu chuyển 100l dầu từ bể 1 sang bể 2 thì bể 2 sẽ nhiều hơn bể 1 là 500l.Hỏi lúc lượng dầu trong bể 1 bằng bao nhiêu phần trăm lượng dầu trong bể 2 ?

tìm x biết : 198 x 11 - 98 x 11 + X : 2 = 1175

Phân tích đa thức thành nhân tử : 3x² - 22 xy - 4x + 8y + 7y² +1