Các bạn ai giúp mình làm với, cám ơn nhiều...
Đọc tiếp
Các bạn ai giúp mình làm với, cám ơn nhiều ^^
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
AD
CÁC BẠN ƠI! CÁC BẠN GIÚP MÌNH LÀM BÀI NÀY VỚI! CÁM ƠN CÁC BẠN RẤT NHIỀU!
1
4T
1
TK
17 tháng 9 2021
<Bạn tự tóm tắt nha>
MCD RntRntR
Số chỉ vôn kế ở 2 đầu đèn 1 và đèn 2
\(U_{12}=U_1+U_2\)
Số chỉ vôn kế của 2 đầu đèn 2 và đèn 3
\(U_{23}=U_3+U_2\)
Vì đây là mạch nối tiếp nên I=I1=I2=I3
mà các đèn giống nhau nên
\(U_1=U_2=U_3=a\)
Lập tỉ lệ ta dc:\(\dfrac{U_{12}}{U_{23}}=\dfrac{U_2+U_1}{U_2+U_3}=\dfrac{a+a}{a+a}=1\Rightarrow U_{12}=U_{23}\)
Vậy số chỉ của 2 vôn kế là bằng nhau
18 tháng 2 2016
ra 34 và - 20
mk làm rùi đó ,bài dưới ế ,rõ ràng rành mạch lên pạn mk nha
18 tháng 2 2016
|7- x|=(-13)-5.(-8)
|7- x|=144
7- x=144
x=7-144
x=(-137)
Vậy : x=(-137); x=137
21 tháng 10 2016
Bài 2:
Đặt \(\frac{a}{b}=\frac{c}{d}=k\Rightarrow\begin{cases}a=kb\\c=kd\end{cases}\)
=> \(\frac{5a+3b}{5a-3b}=\frac{5kb+3b}{5kb-3b}=\frac{b\left(5k+3\right)}{b\left(5k-3\right)}=\frac{5k+3}{5k-3}\left(1\right)\)
\(\frac{5c+3d}{5c-3d}=\frac{5kd+3d}{5kd-3d}=\frac{d\left(5k+3\right)}{d\left(5k-3\right)}=\frac{5k+3}{5k-3}\left(2\right)\)
Từ (1) và (2) => \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
21 tháng 10 2016
Bài 3:
Đặt \(\frac{a}{b}=\frac{b}{c}=\frac{c}{d}=k\)
=> \(\frac{a}{b}.\frac{b}{c}.\frac{c}{d}=k^3\)
=> \(\frac{a}{d}=k^3\) (1)
Lại có: \(\frac{a+b+c}{b+c+d}=\frac{a}{b}=\frac{b}{c}=\frac{c}{d}=k\)
=> \(\left(\frac{a+b+c}{b+c+d}\right)^3=k^3\) (2)
Từ (1) và (2) => \(\frac{a}{d}=\left(\frac{a+b+c}{b+c+d}\right)^3\)
BT
0
18 tháng 5 2016
Goi 4 so tu nhien lien tiep la x; x+1; x+2; x+3. Ta co:
\(x\left(x+1\right)\left(x+2\right)\left(x+3\right)=1990\)
\(x=5,272785471\)
Vay khong co 4 so tu nhien lien tiep co h la 1990
20 tháng 1 2017
(-98).(1-246)-246.98
[(1-246)-246].[(-98)+98)
1.0
0
VIẾT CÁC TÍCH SAU ĐÂY DƯỚI DẠNG MỘT LŨY THỪA
(-5)^5
237.(-26)+26.137
(237-137).(-26+26)
100.0
0
20 tháng 1 2017
\(\left(-98\right).\left(1-246\right)-246.98\)
\(\left(-98\right).\left(-245\right)-246.98\)
\(98.245-246.98\)
\(98.\left(245-246\right)\)
\(98.\left(-1\right)\)
\(\Leftrightarrow=-98\)
\(\left(-5\right).\left(-5\right).\left(-5\right).\left(-5\right).\left(-5\right)\)
\(=\left(-5\right).5\)
\(=-25\)
\(\left(-2\right).\left(-2\right).\left(-2\right).\left(-3\right).\left(-3\right).\left(-3\right)\)
\(=\left(-2\right).3.\left(-3\right).3\)
\(=54\)
\(237.\left(-26\right)+26.137\)
\(=-6162+3562\)
\(=-2600\)
NN
2
TG
25 tháng 12 2018
I. PHONES ( 1pt)
A. Choose the word which underline part is pronounced differently from the others.
1. a. house b. happy c. hour d. how
2. a. recess b. celebration c. relax d. rehearse
B. Choose the word which is stressed differently from the others.
1. a. physics b. novel c. order d. biology
2. a. collector b. marbles c. experiment d. recess
II. Choose the best answer (3pts)
1. In_________, we study different countries and our people.
a. math b. music c. chemistry d. geography
2. I have five periods______ Friday.
a. at b. in c. on d. to
3. Talking is________ common way of relaxing.
a. more b. most c. the most d. the more
4. Let’s________ to the movie.
a. go to b. go c. going d. is going
5. My brother is good________English.
a. at b. with c. on d. very
6. The Mekong River is the________ river in Viet Nam.
a. long b. longer c. most long d. longest
7. Would you ________ a cold drink?
a. get b. to get c. getting d. gets
8. ________do your classes start ? – At seven o’clock.
a. How often b. What c. What time d. Which
9. That’s a___________. Why don’t we travel by bus?
a. thinking b. answer c. good idea d. question
10. Students have two_______ each day.
a. 20-minutes break b. 20-minute breaks
c. 20-minute break d. 20-minutes breaks
11. His ideas are quite________ from my ideas.
a. same b. different c. d. as
12. After break, everyone goes_________ and classes start again.
a. indoor b. indoors c. outdoor d. outdoors
III. Supply the correct form of the words. (0.5m)
1. The most popular_______ at recess is talking. ( act)
2. History is an________ subject. (interest)
IV. Put the passage with the words given in the box (1.5pts)
(lasts/ uniform/ Vietnamese/ two/ recess/ some)
School in Viet Nam are different from school in the USA. (1) ……….……… students always wear school (2)………………….There are no lessons on Sunday. Classes start at 7 o’clock each morning and end at 11.30 . Students have (3)…………………..breaks each morning. At (4)…………..……, students often go to the canteen and buy (5)….……………..things to eat or drink. Our school year (6)………………. for ten months from August to May.
V. Read the passage , then answer the questions. (1.5pts)
Lan’s classes all start at 8:00 a.m, so she gets up at 7:00. She eats a quick breakfast and takes the bus to her school. In the afternoon, she has a job at the library. She usually studies in the evening. She works at the library on Saturdays, too.
She usually stays up late every evening. She usually goes to bed at 11:30 and on Sundays she sleeps until noon.
Questions
1. Does Lan have a job at school or the library?
………………………………………………………………………………………………………………………….…..
2. How does she go to school?
……………………………………………………………………………………………………………………………....
3. Where does she work on Saturdays?
…………………………………………………………………………………………………………………………………
VI. Rewrite the sentences. (2pts)
1. Should we go to the movie?
Let’s …………………………………………………………………………………………………..……....
2. Mr John is going to visit his grandparents tonight.
Mr John will …………………………………………………………………………………………………
3. We have a break that lasts thirty minutes.
We have a ……………………………………………………………………………………………………
4. When is your birthday?
What’s…………………………………………………………………………………………………………?
VII. Complete the sentences. (0.5pt)
1. Let’s/ go/ cafeteria/ and/ get/ cold drink.
………………………………………………………………………………………………………………………
2. Marry/ learn/ play/ piano/ every afternoon.
……………………………………………………………………………………………………………………..
THE END
Full name: ………………… Class: 7…….……………… | THE SECOND 45-MINUTE TEST Date: ……………………….. | Marks |
I. PHONES (1pt)
A. Choose the word which underline part is pronounced differently from the others.
1. a. hour b. happy c. house d. how
2. a. recess b. celebration c. relax d. rehearse
B. Choose the word which is stressed differently from the others.
a. physics b. biology c. order d. novel
a. experiment b. marbles c. collector d. recess
II. Rewrite the sentences. (2pts)
1. Should we go to the movie?
Let’s …………………………………………………………………………………………………..……....
2. Mr John is going to visit his grandparents tonight.
Mr John will …………………………………………………………………………………………………
3. We have a break that lasts thirty minutes.
We have a ……………………………………………………………………………………………………
4. When is your birthday?
What’s…………………………………………………………………………………………………………?
III. Complete the sentences. (0.5pt)
1. Let’s/ go/ cafeteria/ and/ get/ cold drink.
………………………………………………………………………………………………………………………
2. Marry/ learn/ play/ piano/ every afternoon.
……………………………………………………………………………………………………………………..
IV. Put the passage with the words given in the box (1.5pts)
(lasts/ uniform/ Vietnamese/ two/ recess/ some)
School in Viet Nam are different from school in the USA. (1) ……….……… students always wear school (2)………………….There are no lessons on Sunday. Classes start at 7 o’clock each morning and end at 11.30 . Students have (3)…………………..breaks each morning. At (4)…………..……, students often go to the canteen and buy (5)….……………..things to eat or drink. Our school year (6)………………. for ten months from August to May.
V. Read the passage , then answer the questions. (1.5pts)
Lan’s classes all start at 8:00 a.m, so she gets up at 7:00. She eats a quick breakfast and takes the bus to her school. In the afternoon, she has a job at the library. She usually studies in the evening. She works at the library on Saturdays, too.
She usually stays up late every evening. She usually goes to bed at 11:30 and on Sundays she sleeps until noon.
Questions
1. Does Lan have a job at school or the library?
………………………………………………………………………………………………………………………….…..
2. How does she go to school?
……………………………………………………………………………………………………………………………....
3. Where does she work on Saturdays?
…………………………………………………………………………………………………………………………………
VI. Choose the best answer (3pts)
1._________ do your classes start ? – At seven o’clock.
a. How often b. What c. What time d. Which
2. That’s a___________. Why don’t we travel by bus?
a. thinking b. answer c. good idea d. question
3. Students have two______ each day.
a. 20-minutes break b. 20-minute breaks
c. 20-minute break d. 20-minutes breaks
4. Your ideas are quite_________ from my ideas.
a. same b. different c. d. as
5. After break, everyone goes_______ and classes start again.
a. indoor b. indoors c. outdoor d. outdoors
6. In_______, we study different countries and our people.
a. math b. music c. chemistry d. geography
7. I have five periods________Priday.
a. at b. in c. on d. to
8. Talking is_______ common way of relaxing.
a. more b. most c. the most d. the more
9. Let’s________ to the movie.
a. go to b. go c. going d. is going
10. My brother is good________ English.
a. at b. with c. on d. very
11. The Mekong River is the_______ river in Viet Nam.
a. long b. longer c. most long d. longest
12. Would you _______ a cold drink?
a. get b. to get c. getting d. gets
VII. Supply the correct form of the words. (0.5m)
1. The most popular_______ at recess is talking. (act)
2. History is an__________ subject. (interes)