Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Một giờ người thứ nhất làm được \(1:\frac{2}{5}\) = \(\frac{5}{2}\left(cv\right)\)
=> 12 min người thứ nhất làm được \(\frac{5}{2}.\frac{1}{5}\)=\(\frac{1}{2}\left(cv\right)\)
Số phần công việc còn lại: \(1-\frac{1}{2}=\frac{1}{2}\)
Người thứ hai làm một mình hết: \(1:[(\frac{1}{2}:\frac{1}{9})-\frac{5}{2}]\) =\(\frac{1}{2}\) (h)
I
1.B
2.C
3.A
II
1.A , Used to
2.C Going
3.B .Housework
4.C. Subject
5.B. Good
III.
1. Many _homeless____ families have to live in tents
2. He was very _proud____ of the work he had done.
3. Freedom of _____speech__ is one of the fundamental rights.
4. His sense of __humor__ him from other students.
IV: Give the correct form/ tense of the verbs.
1. They asked us (not go) ...not to go... out alone at night.
2. The children were excited about (open) ..opening........ their presents.
3. She ..has just had........ (just have) dinner.
4. ko bk
V: Complete the second sentence so that it has a similar meaning to the first one.
1. '' How much do you think it will cost? '' he said to me.
- He asked me_how much I thought it would cost_
2. It takes minh 2 hours to do his homework every day.
- Minh spends _2 hours doing his homework every day
3,4,5 ko bk. Chỉ bk chừng đó thôi
Ta có: \(pq+q=13+q^2\Leftrightarrow q\left(p+1\right)=13+q^2\)
Vì\(q^2⋮q\Leftrightarrow13⋮q\Leftrightarrow\left[{}\begin{matrix}q=1\\q=13\end{matrix}\right.\)
Nếu q =1 thì:\(p+1=14\Leftrightarrow p=13\)
\(\Rightarrow pq=13\left(cm^2\right)\)(1)
Nếu q=13 thì:\(13p+13=182\Leftrightarrow p=13\)
\(\Rightarrow pq=169\left(cm^2\right)\)(2)
Từ (1)(2) ta có: \(max\left(pq\right)=169\left(cm^2\right)\)
Bạn xem hộ mình sai ở đâu k
kẻ AC cắt MN tại I
ta có \(\dfrac{AM}{MD}=\dfrac{BN}{NC}\left(=\dfrac{1}{2}\right)\Rightarrow\)MN//DC//AB(định lí Talet đảo)
ta có:
\(\dfrac{AM}{MD}=\dfrac{1}{2}\Rightarrow\dfrac{AM}{AD}=\dfrac{AM}{AM+MD}=\dfrac{1}{1+2}=\dfrac{1}{3}\\ \Rightarrow\dfrac{BN}{BC}=\dfrac{1}{3}\Rightarrow\dfrac{NC}{BC}=\dfrac{2}{3}\)
tam giác ADC có MI//DC nên :\(\dfrac{MI}{DC}=\dfrac{AM}{AD}\Rightarrow\dfrac{MI}{\left(x+2\right)\left(x-2\right)}=\dfrac{1}{3}\Rightarrow\left(x+2\right)\left(x-2\right)=3MI\)
tam giac CAB có IN//AB nên:
\(\dfrac{NI}{AB}=\dfrac{BN}{BC}\Rightarrow\dfrac{NI}{x+4}=\dfrac{2}{3}\Rightarrow2\left(x+4\right)=3NI\)
\(\left(x+2\right)\left(x-2\right)+2\left(x+4\right)=3MI+3NI\\ \Leftrightarrow x^2-4+2x+8=3\left(MI+NI\right)=3MN=39\\ \Leftrightarrow x^2+2x+4-39=0\\ \Leftrightarrow x^2+2x-35=0\\ \Leftrightarrow\left(x-5\right)\left(x+7\right)=0\Leftrightarrow\left[{}\begin{matrix}x=5\\x=-7\end{matrix}\right.\)
Vậy x=5 hoặc x=-7
1)I think he will leave as soon as he know the news
2)He will come and see you soon
1. has worked
2. leave / know
3. were singing
4. have (never) seen
5. has worked / retired
6. have just lost
7. am studying
8. do (you) live / live
9. is (he) doing / is watering
10. does (she) do / is
11. Are / am not
1. They traveled to Mexico last summer
2. I had a little trouble with my car last week
3. He has this car for 2 years
4. How long did you live in this house?-Since 1985
5. Yesterday, I met Mr. Tan at the airport. I haven't met him for nearly one year
6. Did You see Lan recently?-Yes, I saw her yesterday
7. He already finish his homework ???? (Sai đề?)
8. Have You eat lunch yet?-No yet
9. Why you didn't go to work yesterday?-I was sick
10. My hands are dirty. I have repaired my car
Sai thì thôi nha
1. As soon as Phuc finished his housework, he went to work.
2. They were doing their English homework when their children were playing football last afternoon.