Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
em xin gop y the nay :
day la phan TA chu ko phai la Toan, mong anh/chi thong cam
neu can anh chi co the la thanh vien trong Online Math
EM XIN CAM ON
A = 1 + 3 + 32 + 33 +...+ 32011 + 32012
A = ( 1 + 3 + 32 ) + ( 33 + 34 + 35 ) +...+ ( 32010 + 32011 + 32012 )
A = ( 1 + 3 + 32 ) + 33 . ( 1 + 3 + 32 ) +...+ 32010 . ( 1 + 3 + 32 )
A = 13 + 33 . 13 +...+ 32010 . 13
A = 13 + ( 33 +...+ 32010 ) . 13
Vì 13 \(⋮\)13 nên 13 + ( 33 +...+ 32010 ) . 13 \(⋮\)13
hay A \(⋮\)13
~ Hok tốt ~
M= 1 - 1/2 + 1/2 - 1/3 +1/3 -1 /4 + 1/4 - 1/5 + .....+ 1/10 - 1/11 + 1/11 -1/12
= 1 - 1/12
= 11/12
Bài 1 :
\(S=\frac{2}{1.2.3}+\frac{2}{2.3.4}+...+\frac{2}{2009.2010.2011}\)
\(=\frac{1}{1.2}-\frac{1}{2.3}+\frac{1}{2.3}-\frac{1}{3.4}+...+\frac{1}{2009.2010}-\frac{1}{2010.2011}\)
\(=\frac{1}{1.2}-\frac{1}{2010.2011}<\frac{1}{2}\)
Vậy \(S<\frac{1}{2}\)
Bài 2:
Làm nhiều rồi vào trong chỗ góc học tập của tớ mà coi 
I. Chọn đáp án chính xác nhất điền vào chỗ trống
1. I……………eleven years old.
A. is
B. are
C. am
2. They……......students.
A. am
B. is
C. are
3. Hello, …………..name’s Hoa.
A. I
B. My
C. Me
4. What ……her name?
A. is
B. am
C. are
5. Hello, Mary. ………….is Peter.
A. That
B. This
C. There
6. Good………….Miss. Lan. How are you?
A. Bye
B. night
C. Morning
7. She is eighteen ……………old.
A. year
B. years
C. day
8. Nineteen minus six equals…………
A. twelve
B. thirteen
C. Fourteen
II. Chọn đáp án chính xác nhất điền vào chỗ trống
1. What . . . . . . . names ? – They’re Mai and Nga .
A. are / their
B. is / your
C. are / they
D. Both (A) and (C)
2. Which word has the final sound /s / ?
A. armchairs
B. names
C. thanks
D. erasers
3. There are. . . . . . . . . ……….. students in my school this school year.
A. nine hundred and ninety-nine
B. nine hundreds and ninety-nine
C. nine hundred ninety-nine
D. nine hundred and ninety-nines
4. How . . . . . … you ? I am twelve years old .
A. are
B. old are
C. is
D. old is
5. What ………..they………….. ? – They’re doctors .
A. do / do
B. does / do
C. do / does
D. does / does
6. What is this ? This is . . . . . . . . . eraser.
A. a
B. the
C. an
D. Ø
7. I am ………………… brother.
A. my
B. her
C. he
D. you
8. Where………… he ………. ?
A. do / live
B. does / lives
C. do / lives
D. does / live
9. We live ………………Le Loi street………QuyNhonCity
A. on / in
B. at / in
C. in / at
D. to /in
10. How many……… ………. there in your school?
A. student - is
B. students - are
C. students - is
D. are - students
III. Đặt câu hỏi cho phần được gạch chân trong các câu sau.
1. Mr. Hai travels to work by car every morning.
…………………………………………
2. They often go swimming in the summer.
…………………………………………
3. My mother needs an apple.
..................................................................
4. Jane’s sister works in a hospital.
……………………………………………
5. These students have English classes on Tuesday and Friday
……………………………………………
IV. Viết lại những câu sau sao cho nghĩa không thay đổi so với câu cho trước, bắt đầu bằng những từ gợi ý.
1. My sister often walks to the supermarket.
=> My sister often goes ...............................
2. Does your class have fifty students?
=> Are .........................................................
3. Mrs. Hoa goes to work at six forty-five.
=> Mrs. Hoa goes to work at a ....................
4. He is in the bath at the moment.
=> He is .............................. a .....................
5. What is the price of the kets ?
=> How much ............................................
V. Đọc đoạn văn ngắn sau và trả lời các câu hỏi
This is a photo of my family. This is my father. He’s 40 years old. He’s a doctor. And this is my mother. She’s 35. She’s a doctor, too. These are my brother, Tom and my sister, Mary. Tom’s 10 and Mary’s 7. They’re students.
1. How many people are there in his family? ……………………………..…………………
2. How old is his father?……………………………..……………………………………….
3. What does his mother do?……………………………..…………………………………..
4. How old is his brother and his sister?……………………………..…………………….…
------- HẾT --------
Đề khảo sát chất lượng đầu năm môn tiếng Anh - Số
Choose the word whose underlined part is pronounced differently (1.0 point)
1.
a. some
b. rod
c. come
d. month
2.
a. judo
b. hope
c. post
d. one
3.
a. school
b. chess
c. teaching
d. chalk
4.
a. physics
b. history
c. excited
d. music
5.
a. healthy
b. history
c. vocabulary
d. my
II. Odd one out (1.0 point)
1. a. compass
b. textbook
c. calculator
d. judo
2. a. English
b. Play
c. science
d. history
3. a. have
b. share
c. with
d. study
4. a. classmate
b. remember
c. knock
d. help
5. a. Uniform
b. post office
c. library
d. classroom
III. Choose the best answer A, B, C or D to complete the entences below (3.0 points)
1. Listen! Someone______ at the door.
a. are knocking
b. is knocking
c. knock
d. knocks
2. ________. I forgot my calculator.
a. Oh dear
b. I see
c. You'll see
d. That's OK
3. I'm excited _________ our first day at school.
a. in
b. with
c. about
d. for
4. Let's _______ our school uniform and go to school.
a. take off
b. wear on
c. put off
d. put on
5. Get up, Tom. We ________ to school, today.
a. are going back
b. going back
c. go to back
d. are going to back
6. I meet my friend ______ my way to school
a. in
b. On
c. at
d. ___
7. Do you ______ your things with your classmates?
a. share
b. help
c. put on
d. wear
8. My school is _______ by mountains and green fields.
a. surrounding
b. surround
c. Surrounded
d . surrounds
9. How do you get to school every day? – ___________
a. By bike
b. On foot
c. I walk to school
d. all are correct
10. I ______ my homework with my friends.
a. Play
b. have
c. do
d. all are correct
11. Students live and study in a ____________ school. They only go home at weekends.
a. Boarding
b. international
c. creative
d. small
12. ________ does Mai usually cook dinner? – At five pm.
a. What
b. When
c. What time
d. Why
13. They are healthy because they _______ every day.
a. Play chess
b. do judo
c. study vocabulary
d. play music
I. Chọn đáp án chính xác nhất điền vào chỗ trống
1. I……………eleven years old.
A. is
B. are
C. am
2. They……......students.
A. am
B. is
C. are
3. Hello, …………..name’s Hoa.
A. I
B. My
C. Me
4. What ……her name?
A. is
B. am
C. are
5. Hello, Mary. ………….is Peter.
A. That
B. This
C. There
6. Good………….Miss. Lan. How are you?
A. Bye
B. night
C. Morning
7. She is eighteen ……………old.
A. year
B. years
C. day
8. Nineteen minus six equals…………
A. twelve
B. thirteen
C. Fourteen
II. Chọn đáp án chính xác nhất điền vào chỗ trống
1. What . . . . . . . names ? – They’re Mai and Nga .
A. are / their
B. is / your
C. are / they
D. Both (A) and (C)
2. Which word has the final sound /s / ?
A. armchairs
B. names
C. thanks
D. erasers
3. There are. . . . . . . . . ……….. students in my school this school year.
A. nine hundred and ninety-nine
B. nine hundreds and ninety-nine
C. nine hundred ninety-nine
D. nine hundred and ninety-nines
4. How . . . . . … you ? I am twelve years old .
A. are
B. old are
C. is
D. old is
5. What ………..they………….. ? – They’re doctors .
A. do / do
B. does / do
C. do / does
D. does / does
6. What is this ? This is . . . . . . . . . eraser.
A. a
B. the
C. an
D. Ø
7. I am ………………… brother.
A. my
B. her
C. he
D. you
8. Where………… he ………. ?
A. do / live
B. does / lives
C. do / lives
D. does / live
9. We live ………………Le Loi street………QuyNhonCity
A. on / in
B. at / in
C. in / at
D. to /in
10. How many……… ………. there in your school?
A. student - is
B. students - are
C. students - is
D. are - students
III. Đặt câu hỏi cho phần được gạch chân trong các câu sau.
1. Mr. Hai travels to work by car every morning.
…………………………………………
2. They often go swimming in the summer.
…………………………………………
3. My mother needs an apple.
..................................................................
4. Jane’s sister works in a hospital.
……………………………………………
5. These students have English classes on Tuesday and Friday
……………………………………………
IV. Viết lại những câu sau sao cho nghĩa không thay đổi so với câu cho trước, bắt đầu bằng những từ gợi ý.
1. My sister often walks to the supermarket.
=> My sister often goes ...............................
2. Does your class have fifty students?
=> Are .........................................................
3. Mrs. Hoa goes to work at six forty-five.
=> Mrs. Hoa goes to work at a ....................
4. He is in the bath at the moment.
=> He is .............................. a .....................
5. What is the price of the kets ?
=> How much ............................................
V. Đọc đoạn văn ngắn sau và trả lời các câu hỏi
This is a photo of my family. This is my father. He’s 40 years old. He’s a doctor. And this is my mother. She’s 35. She’s a doctor, too. These are my brother, Tom and my sister, Mary. Tom’s 10 and Mary’s 7. They’re students.
1. How many people are there in his family? ……………………………..…………………
2. How old is his father?……………………………..……………………………………….
3. What does his mother do?……………………………..…………………………………..
4. How old is his brother and his sister?……………………………..…………………….…
------- HẾT --------
Đề khảo sát chất lượng đầu năm môn tiếng Anh - Số
Choose the word whose underlined part is pronounced differently (1.0 point)
1.
a. some
b. rod
c. come
d. month
2.
a. judo
b. hope
c. post
d. one
3.
a. school
b. chess
c. teaching
d. chalk
4.
a. physics
b. history
c. excited
d. music
5.
a. healthy
b. history
c. vocabulary
d. my
II. Odd one out (1.0 point)
1. a. compass
b. textbook
c. calculator
d. judo
2. a. English
b. Play
c. science
d. history
3. a. have
b. share
c. with
d. study
4. a. classmate
b. remember
c. knock
d. help
5. a. Uniform
b. post office
c. library
d. classroom
III. Choose the best answer A, B, C or D to complete the entences below (3.0 points)
1. Listen! Someone______ at the door.
a. are knocking
b. is knocking
c. knock
d. knocks
2. ________. I forgot my calculator.
a. Oh dear
b. I see
c. You'll see
d. That's OK
3. I'm excited _________ our first day at school.
a. in
b. with
c. about
d. for
4. Let's _______ our school uniform and go to school.
a. take off
b. wear on
c. put off
d. put on
5. Get up, Tom. We ________ to school, today.
a. are going back
b. going back
c. go to back
d. are going to back
6. I meet my friend ______ my way to school
a. in
b. On
c. at
d. ___
7. Do you ______ your things with your classmates?
a. share
b. help
c. put on
d. wear
8. My school is _______ by mountains and green fields.
a. surrounding
b. surround
c. Surrounded
d . surrounds
9. How do you get to school every day? – ___________
a. By bike
b. On foot
c. I walk to school
d. all are correct
10. I ______ my homework with my friends.
a. Play
b. have
c. do
d. all are correct
11. Students live and study in a ____________ school. They only go home at weekends.
a. Boarding
b. international
c. creative
d. small
12. ________ does Mai usually cook dinner? – At five pm.
a. What
b. When
c. What time
d. Why
13. They are healthy because they _______ every day.
a. Play chess
b. do judo
c. study vocabulary
d. play music
\(B1:\)-Ta xát tổng của M
48 chia hết cho 4
20 chia hết cho 4
Ta áp dụng công thức a chia hết cho d;b chia hết cho d;c chia hết cho d
=>a+b+c chia hết cho d
=>Để m chia hết cho 4 thì a cũng phải chia hết cho 4
Để M không chia hết cho 4 thì a phải không chia hết cho 4
\(B2:\)1x2x3x4x5x...x20
=(5x20x4)x1x2x3x...
=400x1x2x3x...
Ta có 400 chia hết cho 400
Ta áp dụng công thức
a chia hết cho b thì a nhân với bất kì số nào cũng chia hết cho b
=>A chia hết cho 400
\(B3:\)Ta có n+10 chia hết cho n+1;n+1 chia hết cho n+1
=>(n+10)-(n+1) chia hết cho n+1
a,(n+10)-(n+1)=9
=>9 là bội của n+1
Ư(9)=(1;-1;3;-3;9;-9)
| n+1 | 1 | -1 | -3 | 3 | 9 | -9 | |
| n | 0 | -2 | -4 | 2 | 8 | -10 |
=.n=(0;-2;-4;2;8;-10
