K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
27 tháng 7 2018
h) Ta có: \(\left\{{}\begin{matrix}\left|x-7\right|=\left|7-x\right|\ge7-x\\\left|x+5\right|\ge x+5\end{matrix}\right.\)
\(\Rightarrow\left|7-x\right|+\left|x+5\right|\ge\left(7-x\right)+\left(x+5\right)\)
\(\Rightarrow\left|x-7\right|+\left|x+5\right|\ge12\)
\(\Rightarrow H\ge12\)
Dấu "=" xảy ra \(\Leftrightarrow\left\{{}\begin{matrix}7-x\ge0\\x+5\ge0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\le7\\x\ge-5\end{matrix}\right.\)
\(\Leftrightarrow-5\le x\le7\)
Vậy, MinH = 12 \(\Leftrightarrow-5\le x\le7\)
27 tháng 7 2018
a) Ta có: \(A=2x^2-8x+10\)
\(=2\left(x^2-4x+5\right)\)
\(=2\left(x^2-4x+2^2+1\right)\)
\(2\left[\left(x-2\right)^2+1\right]\)
Ta lại có: \(\left(x-2\right)^2\ge0\)
\(\Rightarrow2\left[\left(x-2\right)^2+1\right]\ge2\)
\(\Rightarrow A\ge2\)
Dấu bằng xảy ra \(\Leftrightarrow\left(x-2\right)^2=0\)
\(\Leftrightarrow x-2=0\)
\(\Leftrightarrow x=2\)
Vậy MinA = 2 \(\Leftrightarrow x=2\)
29 tháng 7 2018
Bạn nào cho mk 1 ik, mk cho bn ý 3 ik luôn. Mk hứa nếu nói dối bạn có thể Báo cáo sai phạm mk.
DA
21 tháng 7 2021
1:How much/ time/ day/ you/ spend/ playing game?
A. How much time a day do you spend on playing game?
B. How much time a day do you spend in playing game?
C. How much time a day did you spend in playing game?
D. How much time a day did you spend on playing game?
2: Nick/ just/ buy/ a CD/ Vietnamese folk songs/ and he/ think/ he/ enjoy/ listen/ to the melodies.
A. Nick just bought a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.
B. Nick has just bought a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.
C. Nick did just buy a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.
D. Nick just buys a CD of Vietnamese folk songs and he thinks he’ll enjoy listening to the melodies.
3: Ping/ not/ mind/ do/ a lot of/ homework/ in the evenings.
A. Ping doesn’t mind to do a lot of homework in the evenings.
B. Ping didn’t mind to do a lot of homework in the evenings.
C. Ping didn’t mind doing a lot of homework in the evenings.
D. Ping doesn’t mind doing a lot of homework in the evenings
4: Marie/ / window shopping/ her close friend/ Saturday evenings.
A. Marie s window shopping with her close friend in Saturday evenings.
B. Marie window shopping with her close friend in Saturday evenings.
C. Marie s window shopping with her close friend on Saturday evenings.
D. Marie window shopping with her close friend on Saturday evenings.
5: Why/ not/ we/ help/ our parents/ some DIY projects?
A. Why not we help our parents with some DIY projects?
B. Why not we help our parents some DIY projects?
C. Why don’t we help our parents some DIY projects?
D. Why don’t we help our parents with some DIY projects?
Rearrange the sentences to make meaningful sentences
6:look/ does/ she/ what/ ?
A. What she look does?B. What does she look ?
C. What does she look?D. What she look does ?
7: a/ received/ Lan/ letter/ yesterday/ her/ from/ friend.
A. Lan a letter received her friend from yesterday.
B. Lan her friend received a letter from yesterday.
C. Lan received a her friend letter from yesterday.
D. Lan received a letter from her friend yesterday.
8: is/ My/ gardening/ activity/ favourite/ leisure.
A. My favourite leisure activity is gardening.B. My leisure activity favourite is gardening.
C. My gardening is favourite leisure activity.D. My activity is favourite leisure gardening.
9: not/ get/ is/ She/ to/ old/ married/ enough.
A. She is not old to get enough married.B. She is not get married old enough to.
C. She is not old enough to get married.D. She is not enough old to get married.
10: long/ is/ a/ girl/ She/ with/ nice/ hair.
A. She is a nice girl with long hair.B. She is a long hair girl with nice.
C. She is with a nice girl long hair.D. She is with a long hair girl nice.
3 tháng 12 2021
X. Complete the sentences with the past simple or past continuous form of the verbs in brackets.
11. He _was walking_(walk) down the road when he ____heard____(hear) a loud noise.
12. When we _were___(be) in Canana, we _went__(go) skiing almost every day.
13. Where _did__ you __go_(go) last summer holiday, Jim? ~ Well, I _took__(take) a trip to Minneapolis.
14. When I __arrived___(arrive), they ____said____(say) hello but continued working.
15. When you _______met__(meet) me yesterday, I __didn't go___(not go) to school, I ___went__(go) to the doctor’s - I felt terrible.