K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

16 tháng 2

Câu a

A = m\(x^2\) + 2 - 1

\(x=1\) là nghiệm của A khi và chỉ khi:

m.1\(^2\) + 2 - 1 = 0

m + 2 - 1 = 0

m = 1 - 2

m = -1

Vậy m = - 1 thì \(x=1\) là nghiệm của A


16 tháng 2

b; B = \(x^2\) + m\(x\) - 3

\(x=1\) là nghiệm của B khi và chỉ khi

1\(^2\) + m.1 - 3 = 0

1 + m - 3 = 0

m = 3 - 1

m = 2

Vậy với m = 2 thì \(x=1\) là nghiệm của B

13 tháng 2

1 give
2 didn’t want
3 is listening
4 How long has she known
5 has given up
6 are not studying
7 visit
8 has been increasing
9 wanted
10 has already repaired

14 tháng 2

11 give

12 didn't want

13 is listening

14 has she known

15 has given

15 tháng 2

Olm chào em, cảm ơn đánh giá của em về chất lượng bài giảng của Olm, cảm ơn em đã đồng hành cùng Olm trên hành trình tri thức. Chúc em học tập hiệu quả và vui vẻ cùng Olm em nhé!

11 tháng 2

Vì DE = DF (giả thiết)

DM = DN (giả thiết)

=> DE - DM = DF - DN

=> ME = NF

Xét tam giác DME và tam giác DNF có:

DE = DF (giả thiết)

góc D chung

DM = DN (giả thiết)

=> tam giác DME = tam giác DNF (cạnh - góc - cạnh) => ME = NF (2 cạnh tương ứng) b, Xét tam giác MEF và tam giác NFE có: ME = NF (chứng minh trên)

EF chung

MF = NE (chứng minh trên)

=> tam giác MEF = tam giác NFE (cạnh - cạnh - cạnh) c, I: Xét tam giác DME và tam giác DNF có: DE = DF (giả thiết)

góc D chung

DM = DN (giả thiết)

=> tam giác DME = tam giác DNF (cạnh - góc - cạnh) => góc DEM = góc DFN (2 góc tương ứng) Mà góc DEM + góc MEN = 180 độ (2 góc kề bù)

góc DFN + góc MFE = 180 độ (2 góc kề bù)

=> góc MEN = góc MFE

Xét tam giác EMI và tam giác FNI có:

ME = NF (chứng minh trên)

góc EMI = góc FNI (2 góc đối đỉnh)

góc MEN = góc MFE (chứng minh trên)

=> tam giác EMI = tam giác FNI (góc - cạnh - góc)

12 tháng 2

a) Xét \(\Delta DNE\) và \(\Delta DMF\) có:

\(DN=DM\left(gt\right)\)

\(\widehat{D}\) chung

\(DE=DF\left(gt\right)\)

\(\Rightarrow\Delta DNE=\Delta DMF\left(c-g-c\right)\)

\(\Rightarrow NE=MF\) (hai cạnh tương ứng)

b) Ta có:

\(ME=DE-DM\)

\(NF=DF-DN\)

Mà \(DE=DF\left(gt\right)\)

\(DM=DN\left(gt\right)\)

\(\Rightarrow ME=NF\)

Xét \(\Delta MEF\) và \(\Delta NFE\) có:

\(ME=NF\left(cmt\right)\)

\(MF=NE\left(cmt\right)\)

\(EF\) là cạnh chung

\(\Rightarrow\Delta MEF=\Delta NFE\left(c-c-c\right)\)

c) Do \(\Delta DNE=\Delta DMF\left(cmt\right)\)

\(\Rightarrow\widehat{DEN}=\widehat{DFM}\) (hai góc tương ứng)

\(\Rightarrow\widehat{MEI}=\widehat{NFI}\)

Do \(\Delta MEF=\Delta NFE\left(cmt\right)\)

\(\Rightarrow\widehat{EMF}=\widehat{FNE}\) (hai góc tương ứng)

\(\Rightarrow\widehat{EMI}=\widehat{FNI}\)

Xét \(\Delta EMI\) và \(\Delta FNI\) có:

\(\widehat{MEI}=\widehat{NFI}\left(cmt\right)\)

\(ME=NF\left(cmt\right)\)

\(\widehat{EMI}=\widehat{FNI}\left(cmt\right)\)

\(\Rightarrow EMI\Delta=\Delta FNI\left(g-c-g\right)\)

\(A=4x^2y\cdot\left(-3xy^2\right)\)

\(=4\cdot\left(-3\right)\cdot x^2\cdot x\cdot y\cdot y^2\)

\(=-12x^3y^3\)

8 tháng 2

Đừng bao giờ coi thường sức mạnh của sự kiên trì! Dù bạn không nhanh nhẹn như người khác, nhưng chỉ cần từng bước bền bỉ tiến lên, bạn sẽ đạt được mục tiêu của mình. Hãy nhớ rằng, chiến thắng không thuộc về kẻ xuất phát nhanh nhất, mà thuộc về người không bao giờ bỏ cuộc!

7 tháng 2

Bây giờ bạn thay đổi thành nhân vật rùa đi, đây là bài văn:

Tôi là một chú rùa chậm chạp. Nhưng vào một ngày nọ, tôi đã thắng trong cuộc thi chạy cùng với người chạy nhanh nhất trong khu rừng chình là thỏ. Câu chuyện diễn ra như sau: Vào một ngày nọ, chú thỏ kiêu ngạo nói với mọi người rằng :"Tôi là người chạy nhanh nhất trong khu vườn này. Có ai muốn chạy thi với tôi để chứng minh lời nói của tôi rất đúng không." Đúng lúc đó tôi đi ngang qua, nghe được những lời hống hách của thỏ tôi bực mình và nói tôi muốn thi với chú. Thỏ cười ngạo tôi và nói: " Ấy ấy tôi không muốn thi với bác đâu. Sợ bác thua, bác buồn, mọi người lại nói tôi thế này thế nọ". Có gì đâu chứ. Chúng ta cứ thi thử xem ai thắng ai bại. Tôi biết tôi sẽ thua nhưng tôi không chịu được sự kiêu ngạo của thỏ. Rồi cuộc thi bắt đầu. tôi chỉ có chạy được mấy bước mà thỏ đã chạy được nửa quãng đường. Thỏ chạy một lúc, rồi chú thấy một cái cây to. Chú nghĩ: "Mình cứ ngồi nghỉ ở đây một lúc rồi chạy tiếp. Có khi đến lúc đó rùa mới chạy chưa được nửa quãng đường". Vì mệt quá, thỏ vừa nằm xuống gốc cây đã ngủ thiếp đi luôn. Cho đến khi tôi dã chạy gần đến đích thì thỏ mới thức dậy. Thỏ giật mình khi thấy tôi đã về gần đến đích. Chú đứng dậy và cố gắng chạy thật nhanh để đuổi kịp tôi. Nhưng không, cuối cùng tôi đã về đến đích. Tôi đã thắng cuộc rồi, tôi rất vui vẻ. Mọi người tung hô tôi và đồng thanh nói: Rùa vô địch! Rùa vô địch! Nhờ sự kiên trì của mình mà tôi đã thắng thỏ. Còn thỏ thì đã nhận được một bài học nhớ đời. thỏ đã hiểu rằng cái gì cũng phải cần sự kiên trì mới thành công. nếu chủ quan bạn sẽ không thể thành công được.

8 tháng 2

A = 2\(x^2\) - 8\(x\) + 1

A = 2(\(x^2-4x+4\)) - 7

A = 2.\(\left(x-2\right)^2\) - 7

\(\left(x-2\right)^2\) ≥ 0 ∀\(x\)

(\(x-2\))\(^2\) - 7 ≥ - 7 ∀\(x\) dấu = xảy ra khi \(x-2=0\rArr x=2\)

Kết luận giá trị nhỏ nhất của biểu thức A = \(2x^2-8x+1\) là -7 xảy ra khi \(x=2\)



c1. I woke ______ late this morning and missed the first bus to school. 2. Can you turn ______ the lights? It's too dark to see anything. 3. We need to give ______ the books to the library before they charge us. 4. She looked ______ her younger brother while her parents went to the grocery store. 5. He decided to give ______ eating junk food to stay healthy and feel better. 6. They set ______ early to reach the beach before it became crowded with tourists. 7. I always take ______ my shoes when...
Đọc tiếp

c1. I woke ______ late this morning and missed the first bus to school. 2. Can you turn ______ the lights? It's too dark to see anything. 3. We need to give ______ the books to the library before they charge us. 4. She looked ______ her younger brother while her parents went to the grocery store. 5. He decided to give ______ eating junk food to stay healthy and feel better. 6. They set ______ early to reach the beach before it became crowded with tourists. 7. I always take ______ my shoes when I enter someone's home as a courtesy. 8. The car broke down on the highway, so we had to call ______ help. 9. She ran ______ her old school friend at the shopping mall last weekend. 10. Please fill ______ this form before submitting your application for the library card. 11. The teacher asked us to write ______ all the important points during the lesson. 12. I don't know how to deal ______ this situation. It's really complicated for me. 13. We put ______ warm jackets because it was freezing cold outside that afternoon. 14. He always looks ______ ______ his grandfather because of his wisdom and kindness. 15. The fire alarm went off when someone tried to light ______ a cigarette indoors. 16. She asked me to pick ______ the package from the post office on my way. 17. They told us to keep ______ of the construction site because it was dangerous. 18. Can you check ______ this new book from the library? It's very popular. 19. We need to hurry ______ if we want to catch the last train tonight. 20. She put ______ her plans to travel because of the sudden change in weather. 21. I always wake ______ early on weekends to enjoy the morning air in the garden. 22. He takes ______ his mother in both looks and personality, which everyone finds amazing. 23. The children ran ______ from the barking dog because they were scared of it. 24. My friend helped me sort ______ my closet and donated some clothes to charity. 25. We came ______ an old diary while cleaning the attic of our house yesterday. 26. I don't want to give ______ the secret, so please don't ask me anymore. 27. She asked me to sit ______ and explain everything that had happened at the meeting. 28. He had to look ______ the word in the dictionary because he didn’t know it. 29. Please hold ______ while I check if the manager is available to speak with you. 30. My computer is slow, so I'll shut it ______ and restart to fix the issue. 31. We decided to stay ______ and watch movies because it was raining heavily outside. 32. The kids always look ______ ______ holidays because they get to play all day long. 2012 CƠ BẢN - FILE SỐ 105 - 13/01/2025 By [3T] – LIFE © All rights reserved! Page 2 33. He asked me to carry ______ with the task while he went to make a call. 34. I was so tired after work that I just wanted to lie ______ for a while. 35. Don’t forget to turn ______ the lights before you leave the room, please. 36. She picked ______ a lovely dress to wear to her cousin’s wedding next weekend. 37. I can’t believe they managed to get ______ ______ cheating on the final exam. 38. Let’s go ______ the instructions once more to make sure we understand everything. 39. He likes to show ______ his new gadgets to his friends whenever they visit him. 40. The teacher asked us to break ______ the problem into smaller parts to solve it. 41. We ran ______ ______ sugar, so I had to borrow some from the neighbor. 42. The baby started to calm ______ after his mother sang him a lullaby. 43. I put ______ some decorations for the party, and everyone said they looked beautiful. 44. Let’s call ______ the meeting since most people can’t attend because of the weather. 45. She found ______ that the store was closed after walking all the way there. 46. He asked me to take care ______ his dog while he went on a business trip. 47. The flight attendants told the passengers to buckle ______ before the plane took off. 48. We should cut ______ ______ eating sweets if we want to stay healthy this year. 49. He couldn’t keep ______ ______ the group because he was walking too slowly uphill. 50. The team worked hard to put ______ the presentation for the annual meeting tomorrow. 51. She accidentally knocked ______ the glass of juice, and it spilled all over the table. 52. Can you hand ______ these flyers to the people waiting outside the event hall? 53. I forgot to put ______ my clothes after doing laundry, so my room looks messy. 54. He ran ______ the bus, but it left before he could get on. 55. They set ______ a tent near the river and enjoyed camping under the stars. 56. We decided to check ______ at the hotel first before exploring the nearby tourist spots. 57. He wanted to work ______ at the gym, so he joined a new fitness class. 58. The kids got ______ from the park completely tired but very happy after playing all day. 59. She had to drop ______ her children at school before heading to the office. 60. I’ll call ______ the customer after lunch to discuss the details of the order. 61. The children grew ______ in a small town surrounded by mountains and beautiful scenery. 62. The students asked the professor to go ______ the answers to the quiz in detail. 63. I need to take ______ the jacket I bought because it doesn’t fit me properly. 64. Please watch ______ for cars while crossing the street. It’s a very busy area. 65. We need to find ______ who left the package at our doorstep this morning. 66. The manager asked us to carry ______ the instructions exactly as mentioned in the email. 67. I need to log ______ to my account to check my emails and notifications. 68. We’ll run ______ the schedule once more to make sure everyone knows their responsibilities. 69. I couldn’t get ______ how beautiful the sunset looked from the top of the hill. 70. She decided to move ______ after realizing that dwelling on the past wasn’t helping her. 71. He tried to look ______ the papers to find the one he had misplaced. 72. The tourists asked for help when they couldn’t figure ______ how to use the map. By [3T] – LIFE © All rights reserved! Page 3 73. We should step ______ and consider all options before making a final decision. 74. She asked me to check ______ ______ her plants while she was on vacation. 75. He didn’t want to turn ______ the offer because it was a great opportunity. 76. They asked the children to calm ______ after they started running around the house wildly. 77. We decided to go ______ for dinner to celebrate my brother’s promotion at work. 78. The little boy started to cry ______ when he couldn’t find his mother in the crowd. 79. Let’s look ______ the issue further before we decide what action to take next. 80. I had to work ______ my presentation all night because it was due the next day. 81. She forgot to pick ______ her keys, so she couldn’t get into her apartment. 82. He asked us to stand ______ and wait for instructions before entering the room. 83. Please keep ______ from the wet floor to avoid slipping and hurting yourself badly. 84. The plane finally took ______ after a long delay caused by the bad weather. 85. I couldn’t figure ______ the puzzle, so I asked my friend for help with it. 86. They asked us to step ______ and help with organizing the event for the community. 87. She promised to call ______ the meeting if more people couldn’t join due to the strike. 88. I had to put ______ a quick meal because there wasn’t much food in the fridge. 89. The lights suddenly went ______, so we lit some candles to brighten the room. 90. Please throw ______ any garbage before leaving the park so it stays clean for everyone. 91. He wanted to hang ______ with his friends after school, but they all had homework. 92. The students were told to sit ______ quietly while waiting for the teacher to arrive. 93. I’ll catch ______ with you later after I finish the work on my desk. 94. She couldn’t take ______ all the information during the meeting because it was too overwhelming. 95. The children were told to put ______ their toys and start cleaning up the playroom. 96. He asked us to give ______ our seats for the elderly passengers on the crowded bus. 97. Let’s sort ______ this problem together so we can find a solution quickly and efficiently. 98. The students decided to join ______ the singing competition being held at their school festival. 99. I had to clean ______ the kitchen after the party because it was a complete mess. 100. We should turn ______ now because we’re going the wrong way to reach the restaurant. giúp mình với=))

9
8 tháng 2

c1. I woke ___up___ late this morning and missed the first bus to school. 

2. Can you turn _____on_ the lights? It's too dark to see anything. 

3. We need to give ___back___ the books to the library before they charge us. 

4. She looked ___after___ her younger brother while her parents went to the grocery store.

5. He decided to give ___up___ eating junk food to stay healthy and feel better. 

6. They set ___off___ early to reach the beach before it became crowded with tourists. 

7. I always take ___off___ my shoes when I enter someone's home as a courtesy. 

8. The car broke down on the highway, so we had to call __for____ help. 

9. She ran __into____ her old school friend at the shopping mall last weekend. 

10. Please fill ___in___ this form before submitting your application for the library card.

8 tháng 2

11. The teacher asked us to write ___down___ all the important points during the lesson.

12. I don't know how to deal ___with___ this situation. It's really complicated for me. 

13. We put ___on___ warm jackets because it was freezing cold outside that afternoon. 

14. He always looks ___up___ __to____ his grandfather because of his wisdom and kindness. 

15. The fire alarm went off when someone tried to light __up____ a cigarette indoors. 

16. She asked me to pick ____up__ the package from the post office on my way.

17. They told us to keep ____out__ of the construction site because it was dangerous. 

18. Can you check ___out___ this new book from the library? It's very popular. 

19. We need to hurry ____up__ if we want to catch the last train tonight.

20. She put ___off___ her plans to travel because of the sudden change in weather.