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a) Sửa đề: C/m tứ giác BEHC nội tiếp
Xét tứ giác BEHC có
\(\widehat{BEC}=\widehat{BHC}\left(=90^0\right)\)
\(\widehat{BEC}\) và \(\widehat{BHC}\) là hai góc cùng nhìn cạnh BC
Do đó: BEHC là tứ giác nội tiếp(Dấu hiệu nhận biết tứ giác nội tiếp)
Phép nhân hoá:
Ví dụ: Bác gấu đang bảo vệ những chú hươu khỏi đàn sói hung ác
- Bước sang thế kỉ XVI, triều đình nhà Lê càng suy yếu thì sự tranh chấp giữa các phe phái phong kiến càng diễn ra quyết liệt.
- Mạc Đăng Dung vốn là một võ quan. Lợi dụng xung đột giữa các phe phái, đã tiêu diệt các thế lực đối lập, thâu tóm mọi quyền hành, cương vị như Tể tướng.
- Năm 1527, Mạc Đăng Dung cướp ngôi nhà Lê, lập ra triều Mạc (Bắc triều).
- Năm 1533, một võ quan triều Lê là Nguyễn Kim chạy vào Thanh Hoá, lập một người thuộc dòng dõi nhà Lê lên làm vua, lấy danh nghĩa "phù Lê diệt Mạc", sử cũ gọi là Nam triều để phân biệt với Bắc triều (nhà Mạc ở phía bắc).
=> Cục diện Nam - Bắc triều hình thành.
Bước sang thế kỉ XVI, triều đình nhà Lê càng suy yếu thì sự tranh chấp giữa các phe phái phong kiến càng diễn ra quyết liệt. Mạc Đăng Dung vốn là một võ quan. Lợi dụng xung đột giữa các phe phái, đã tiêu diệt các thế lực đối lập, thâu tóm mọi quyền hành, cương vị như Tể tướng. Năm 1527, Mạc Đăng Dung cướp ngôi nhà Lê, lập ra triều Mạc (Bắc triều). Năm 1533, một võ quan triều Lê là Nguyễn Kim chạy vào Thanh Hoá, lập một người thuộc dòng dõi nhà Lê lên làm vua, lấy danh nghĩa "phù Lê diệt Mạc", sử cũ gọi là Nam triều để phân biệt với Bắc triều (nhà Mạc ở phía bắc).
2 They live in a small town which has 500 inhabitants
3 The police haven't found the robber who stole $50000
4 I lend her "Hamlet", which is really interesting to read
5 I don't remember he name of the man whom I met at the bus stop
6 Tom told me about the job which he sastifed
1. Oleg has an iron box and he kept his letters in the box
2. They live in a small town which has 500 inhabitants
3. The police haven't found the robber who stole $50000
4. I lend her "Hamlet", which is really interesting to read
5. I don't remember he name of the man whom I met at the bus stop
6. Tom told me about the job which he sastifed
\(11x^2-15x+4=0\)
\(\Leftrightarrow11x^2-11x-4x+4=0\)
\(\Leftrightarrow11x\left(x-1\right)-4\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(11x-4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\11x-4=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{4}{11}\end{matrix}\right.\)
\(S=\left\{1,\dfrac{4}{11}\right\}\)
Đặt C(x)=0
\(\Leftrightarrow11x^2-15x+4=0\)
\(\Leftrightarrow11x^2-11x-4x+4=0\)
\(\Leftrightarrow11x\left(x-1\right)-4\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(11x-4\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\11x-4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\11x=4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{4}{11}\end{matrix}\right.\)
Vậy: Nghiệm của đa thức \(C\left(x\right)=11x^2-15x+4\) là 1 và \(\dfrac{4}{11}\)
1. He (work).........is working................in the office now.
2. My friend(enjoy)............enjoys...........hamburgers very much.
3. The students(look) .........are looking..................up these new words right now.
4. We always (do).......do........English exercises carefully.
5. The sun (rise)..........rises..............in the east.
6. They (talk)...............are talking............to John at the moment.
7. he children(sleep)............sleep................well for two hours every afternoon.
8. My sister(need)..............needs.............some money for books.
9. It(rain)..................rains.........very much in the United States.
10. Linda(write)..............is writing..........to David at this time.
11.Thu (not have)..........doesn't have.................any apples. She (have)...........has.........some oranges.
12. Minh (watch)........watches...........TV every night.He (watch).............is watching...........TV at present.
13. We often(swim).........swim ............in the river, but today we (go).........go..............fishing.
14. They usually(play).......play...........tennis. They(play).........are playing.................tennis at the moment.
15. Nam(ride).......rides...........his bike to school everyday, but today he(walk)........is walking....to school.
16. Almost everyone(work)...........works.......very hard.
17. This book(belong)......belongs..................to me.
18. My brother often(see)............sees.......you and your sister at the supermarket.
19. Mr Brown(teach) .............teaches......us English.
20. Please quiet! The baby(sleep)............is sleeping.................
21. Listen ! Someone(knock)...................is knocking................at the door.
22. Look ! The train (come)..........is coming...................
23. My father (have)..............is having................breakfast at present.
24. You should(learn)........learn........hard to please your parents.
25. You shouldn't (smoke)...........smoke...........cigarrettes.
26. We should (collect)............collec...........spare cans and waste paper.
27. People should(eat).......eat...........alot of fruit and vegetables.
28. What(be)......are.......their jobs?
29. What(your parents/ do)...............................do your parents do....................in their free time?
30. Thuy (travel)..................will travel.........to Hanoi next month.
31. He(visit)............will visit...........his relatives tomorrow.
32. We (come)............will come....................here soon.
33. They( practice)...............practice................speaking English everyday. They(speak)..............will speak...............English fluently someday.
34. My sister can(play)................play.........the piano.
35. What......is............your father(do)................doing........at present?
36. Where(be)..............is..........Mum?- She(cook).........is cooking................in the kitchen.
37. An usually(wash)............washes.........his hands before meals.
38. Hoa !(come)........Come...........in, please!
39. Would you like(come)...........to come..........to my house for dinner?
40. I'd like(drink )..........to drink.............a cup of coffee.
41. The children (like/ eat).....................like eating............candy very much.
42. She(like/ listen)..............like listening...........to music in her free time.
43. What..........do .......you (like / do)...........like to do...............on Sundays?
44. My brother can (ride)............ride..........a bicycle.
45. You must (do)...............do......this exercise carefully.
Chia động từ trong ngoặc :h
1. He (work)...............is working..........in the office now.
2. My friend(enjoy).enjoy......................hamburgers very much.
3. The students(look) .........are looking..................up these new words right now.
4. We always (do)..........do.....English exercises carefully.
5. The sun (rise)..............rises..........in the east.
6. They (talk)..................are talking.........to John at the moment.
7. he children(sleep)...........sleep.................well for two hours every afternoon.
8. My sister(need).............needs..............some money for books.
9. It(rain)..............rains.............very much in the United States.
10. Linda(write).............is writting...........to David at this time.
11.Thu (not have)..................doens't have........any apples. She (have).............has.......some oranges.
12. Minh (watch).........watches..........TV every night.He (watch)...............is watching.........TV at present.
13. We often(swim)..........swim...........in the river, but today we (go)..............are going.........fishing.
14. They usually(palay)................play..tennis. They(play).............are playing.............tennis at the moment.
15. Nam(ride)............rides......his bike to school everyday, but today he(walk).........is walking...to school.
16. Almost everyone(work)...work...............very hard.
17. This book(belong)........belong................to me.
18. My brother often(see).......sees............you and your sister at the supermarket.
19. Mr Brown(teach) ......teaches.............us English.
20. Please quiet! The baby(sleep)...is sleeping..........................
21. Listen ! Someone(knock).......is knocking............................at the door.
22. Look ! The train (come).....is coming........................
23. My father (have).......is having.......................breakfast at present.
24. You should(learn).........learn.......hard to please your parents.
25. You shouldn't (smoke)........smoke..............cigarrettes.
26. We should (collect).........collect..............spare cans and waste paper.
27. People should(eat)........eat..........alot of fruit and vegetables.
28. What(be)...are..........their jobs?
29. What(your parents/ do)..........do your parents do .........................................in their free time?
30. Thuy (travel).............is going to travel..............to Hanoi next month.
31. He(visit)...............will visit........his relatives tomorrow.
32. We (come)..................will come..............here soon.
33. They( practice)............practise...................speaking English everyday. They(speak)....................will speak.........English fluently someday.
34. My sister can(play)........plays.................the piano.
35. What..........is........your father(do).doing......................at present?
36. Where(be)..........is..............Mum?- She(cook)..................is cooking.......in the kitchen.
37. An usually(wash)..............washes......his hands before meals.
38. Hoa !(come)........coming...........in, please!
39. Would you like(come)..............to come.......to my house for dinner?
40. I'd like(drink )......to...drink..............a cup of coffee.
41. The children (like/ eat).............like eating....................candy very much.
42. She(like/ listen)........likes listening.................to music in her free time.
43. What..............do...you (like / do)................like to do..........on Sundays?
44. My brother can (ride).......rides..............a bicycle.
45. You must (do).............do........this exercise carefully.