tìm a,b,c. Giúp mih vs ạ
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
NL
1
LN
1
18 tháng 11 2023
8: \(\left(-4\right)\cdot3\cdot\left(-125\right)\cdot25\cdot\left(-8\right)\)
\(=-4\cdot25\cdot125\cdot8\cdot3\)
\(=-3\cdot100\cdot1000=-300000\)
9: \(-25\cdot8\cdot\left(-125\right)\cdot3\cdot\left(-4\right)\)
\(=-25\cdot8\cdot125\cdot4\cdot3\)
\(=-3\cdot25\cdot4\cdot8\cdot125\)
\(=-3\cdot100\cdot1000=-300000\)
10: \(147\cdot333+233\cdot\left(-147\right)\)
\(=147\left(333-233\right)\)
\(=147\cdot100=14700\)
11: \(-115\cdot27+33\cdot\left(-115\right)\)
\(=\left(-115\right)\left(27+33\right)\)
\(=-115\cdot60=-6900\)
12: \(45\cdot\left(-24\right)+\left(-10\right)\cdot\left(-12\right)\)
\(=-45\cdot2\cdot12+10\cdot12\)
\(=-24\left(45-5\right)\)
\(=-24\cdot40=-960\)
13: \(-\left(-4\right)^2\cdot3^2\cdot\left(-5\right)^3\)
\(=-16\cdot9\cdot\left(-125\right)\)
\(=16\cdot9\cdot125=9\cdot2\cdot8\cdot125=18\cdot1000=18000\)
14: \(2-4+6-8+...-48+50\)
\(=\left(2-4\right)+\left(6-8\right)+...+\left(46-48\right)+50\)
\(=\left(-2\right)+\left(-2\right)+...+\left(-2\right)+50\)
\(=50-2\cdot24=2\)
L
1
18 tháng 12 2021
a: \(A=\dfrac{2x^2+6x-x^2+2x-3-x^2-1}{\left(x-3\right)\left(x+3\right)}:\dfrac{x+3-x+1}{x+3}\)
\(=\dfrac{8x-4}{\left(x-3\right)\left(x+3\right)}\cdot\dfrac{x+3}{4}\)
\(=\dfrac{2x-1}{x-3}\)
16 tháng 6 2018
A B C A' B' C' d d' a b c h h'
\(\Delta\)AB'B và \(\Delta\)BB'C có chung chiều cao hạ từ B' nên \(\frac{AB}{BC}=\frac{S_{AB'B}}{S_{BB'C}}\)
Ta có: \(S_{AB'B}=S_{A'BB'}\)(Cùng chiều cao h hạ từ A và A')
Tương tự: \(S_{BB'C}=S_{B'BC'}\)
Suy ra: \(\frac{AB}{BC}=\frac{S_{AB'B}}{S_{BB'C}}=\frac{S_{A'BB'}}{S_{B'BC'}}=\frac{A'B'}{B'C'}\)(Do \(\Delta\)A'BB' và \(\Delta\)B'BC' có chung chiều cao hạ từ B)
Vậy \(\frac{AB}{BC}=\frac{A'B'}{B'C'}\)(đpcm).
LV
21 tháng 6 2018
Mih vẫn thấy vô lý tại sao tg ABB' và tgBB'c lại có chung chiều cao
9 tháng 12 2021
Tham khảo:
Cố gắng học tập, rèn luyện để trở thành một công dân tốt trong xã hộiGiữ gìn và bảo vệ những truyền thống văn hóa tốt đẹp của quê hương, đất nước.Vệ sinh khu phố mình đang ở cũng như xung quanh, hạn chế thả rác bừa bãiTuyên truyền việc tốt để các bạn nhỏ và mọi người thể hiện tình yêu quê hương đất nước,...9 tháng 12 2021
cô em nói không đc chép mạng ạ, có 1 bn kia chép cô giận quá nên cho 0đ
mn giúp em vs ạ !
25 tháng 12 2017
PHÒNG GD&ĐT
VĨNH TƯỜNG
ĐỀ KIỂM TRA HỌC KỲ I NĂM HỌC 2017-2018
Môn: Tiếng Anh - Lớp 7
Thời gian làm bài: 45 phút (Không kể thời gian giao đề)
A. LISTENING. Listen and fill in each blank with one suitable word to complete the following sentences.
a) The 9.25 flight to (1) ____________ is delayed by (2) ____________ hours
b) Passengers going (3) ____________ should go to boarding gate (4)_________________.
c) Passengers going Athens should go to boarding gate (5)_________________.
d) The flight number of the plane going to Amsterdam is (6)_________________.
e) The time in New York is (7) ______________ .
f) The temperature in (8) ________________ is 760F
B. PHONETICS. Choose the word whose underlined part is pronounced differently from that of the others by write the corresponding letter A or B, C, D.
9. A. delicious B. special C. musical D. physician
10. A. celebration B. collection C. education D. question
11. A. excited B. interested C. worried D. painted
C. VOCABULARY, GRAMMAR. Choose the best answer among A, B, C or D.
12. My tooth doesn’t stop hurting. I’ll go and see the .
A. singer B. teacher C. dentist D. actor
13. Could you tell me how to to the post office?- Oh, it is the left, bookstore and movie theater.
A. reach, on, at B. go, on, in C. reach, on, in D. go, on, between
14. noodles last night?
A. Did you eat B. Were you eat C. Did you ate D. Do you ate
15. It took us an hour to Nha Trang last year.
A. drive B. driving C. to drive D. drove
16. On the table were vegetables, bread and two large .
A. bowl of soup B. bowl of soups C. bowls of soups D. bowls of soup
17. My brother never goes to school late and
A. so do I. B. Neither don’t I. C. I don’t, either D. I don’t, too
18. What a ________________ house!
A. beauty B. beautiful C. beautify D. beautifully
19. I’ve never read a _______ novel than this one.
A. longest B. longer C. most longest D. more longer
20. Mary likes attending the English ____________ contests
A. speaking B. spoken C. speak D. speech
D. READING.
I. Read the passage about Charlie Chaplin and answer the questions
Charlie Chaplin was an English actor, director, producer, and composer. He is known as the most creative person of the silent –film era. Charlie Chaplin’s portrait of the tramp won the hearts of people all over the world.
Chaplin was born in London the 16th of April, 1889.He spent his childhood in poverty and hardship. In 1910 he began to perform pantomime in the United States. He first appeared on screen in 1914. He created his world -famous character, the Tramp, and he played this classic role in more than 70 films during his career. He also composed background music for most of his films. In 1972 Chaplin received an Honorary Academy Award for the “ the incalculable effect he has had in making motion pictures the art form of this century . Chaplin died on the 25th of December, 1977, at his home in Switzerland
21. What did Charlie Chaplin work as?
A. An English actor and director B. An English actor and producer
C. An English actor, director, composer and producer
22. When was he born?
A. April 6th 1889 B. April 16th 1889 C. April 16th 1988
23. When did he start appearing in films?
A. In 1910 B. In 1914 C. In 1972
24. Charlie Chaplin is very famous for __________.
A. his stage performance B. his background music C. his character “the Tramp”
25. Which of the following is NOT true?
A. Charlie Chaplin was an English artist. B. He played classical music.
C. He received an award in 1972.
II. Read, then choose the best answer
VĨNH TƯỜNG
ĐỀ KIỂM TRA HỌC KỲ I NĂM HỌC 2017-2018
Môn: Tiếng Anh - Lớp 7
Thời gian làm bài: 45 phút (Không kể thời gian giao đề)
A. LISTENING. Listen and fill in each blank with one suitable word to complete the following sentences.
a) The 9.25 flight to (1) ____________ is delayed by (2) ____________ hours
b) Passengers going (3) ____________ should go to boarding gate (4)_________________.
c) Passengers going Athens should go to boarding gate (5)_________________.
d) The flight number of the plane going to Amsterdam is (6)_________________.
e) The time in New York is (7) ______________ .
f) The temperature in (8) ________________ is 760F
B. PHONETICS. Choose the word whose underlined part is pronounced differently from that of the others by write the corresponding letter A or B, C, D.
9. A. delicious B. special C. musical D. physician
10. A. celebration B. collection C. education D. question
11. A. excited B. interested C. worried D. painted
C. VOCABULARY, GRAMMAR. Choose the best answer among A, B, C or D.
12. My tooth doesn’t stop hurting. I’ll go and see the .
A. singer B. teacher C. dentist D. actor
13. Could you tell me how to to the post office?- Oh, it is the left, bookstore and movie theater.
A. reach, on, at B. go, on, in C. reach, on, in D. go, on, between
14. noodles last night?
A. Did you eat B. Were you eat C. Did you ate D. Do you ate
15. It took us an hour to Nha Trang last year.
A. drive B. driving C. to drive D. drove
16. On the table were vegetables, bread and two large .
A. bowl of soup B. bowl of soups C. bowls of soups D. bowls of soup
17. My brother never goes to school late and
A. so do I. B. Neither don’t I. C. I don’t, either D. I don’t, too
18. What a ________________ house!
A. beauty B. beautiful C. beautify D. beautifully
19. I’ve never read a _______ novel than this one.
A. longest B. longer C. most longest D. more longer
20. Mary likes attending the English ____________ contests
A. speaking B. spoken C. speak D. speech
D. READING.
I. Read the passage about Charlie Chaplin and answer the questions
Charlie Chaplin was an English actor, director, producer, and composer. He is known as the most creative person of the silent –film era. Charlie Chaplin’s portrait of the tramp won the hearts of people all over the world.
Chaplin was born in London the 16th of April, 1889.He spent his childhood in poverty and hardship. In 1910 he began to perform pantomime in the United States. He first appeared on screen in 1914. He created his world -famous character, the Tramp, and he played this classic role in more than 70 films during his career. He also composed background music for most of his films. In 1972 Chaplin received an Honorary Academy Award for the “ the incalculable effect he has had in making motion pictures the art form of this century . Chaplin died on the 25th of December, 1977, at his home in Switzerland
21. What did Charlie Chaplin work as?
A. An English actor and director B. An English actor and producer
C. An English actor, director, composer and producer
22. When was he born?
A. April 6th 1889 B. April 16th 1889 C. April 16th 1988
23. When did he start appearing in films?
A. In 1910 B. In 1914 C. In 1972
24. Charlie Chaplin is very famous for __________.
A. his stage performance B. his background music C. his character “the Tramp”
25. Which of the following is NOT true?
A. Charlie Chaplin was an English artist. B. He played classical music.
C. He received an award in 1972.
II. Read, then choose the best answer
25 tháng 12 2017
http://d3.violet.vn//uploads/previews/present/4/118/302/preview.swf
5 tháng 8 2019
Ta có: A = x2 - 5x + 1 = (x2 - 5x + 25/4) - 21/4 = (x - 5/2)2 - 21/4
Ta luôn có: (x - 5/2)2 \(\ge\)0 \(\forall\)x
=> (x - 5/2)2 - 21/4 \(\ge\)-21/4 \(\forall\)x
Dấu "=" xảy ra <=> x -5/2 = 0 <=> x = 5/2
Vậy Min A = -21/4 tại x = 5/2
Ta có: B = -x + 3x + 1 = -(x - 3x + 9/4) + 13/4 = -(x - 3/2)2 + 13/4
Ta luôn có: -(x - 3/2)2 \(\le\)0 \(\forall\)x
=> -(x - 3/2)2 + 13/4 \(\le\)13/4 \(\forall\)x
Dấu "=" xảy ra <=> x - 3/2 = 0 <=> x = 3/2
Vậy Max B = 13/4 tại x = 3/2
(xem lại đề)
23 tháng 3 2020
a, tam giác ABC có : ^B = ^C
=> tam giác ABC cân tại A (dh)
=> AB = AC (đn)
xét tam giác ADB và tam giác ADC có : ^B = ^C (gt)
^BAD = ^CAD do AD là pg của ^BAC (gt)
=> tam giác ADB = tam giác ADC (g-c-g)
b, tam giác ADB = tam giác ADC (Câu a)
=> ^ADB = ^ADC (đn)
mà ^ADB + ^ADC = 180 (kb)
=> ^ADB = 90
=> AD _|_ BC
=> AD là đcao của tam giác ABC
Câu hỏi của bạn là gì vậy?