giúp mik nha mn cảm ơn trước
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Tham khảo
1. A special kind of tea is sold here
2. All the cars and trucks have been searched
3. He was put in prison by the goverment last years
4. We will be met by her parents at the station tomorrow
5. A meeting is being held by Mr. Brown in the hall
Bài 2
1 Tea can't be made with cold water
2 Some of my books have been taken away.
3 Some pictures were taken away by the boys.
4 This room may be used for the classroom.
5 This machine mustn't be used after 5:30 p.m
6 Mr Cole used to be visited at weekends by John.
7 All the homework ought to be done by her
Độ dãn của lò xo:
\(F_{đh}=k\cdot\Delta l\Rightarrow\Delta l=\dfrac{F_{đh}}{k}=\dfrac{2}{100}=0,02\)m=2cm
3:
1: \(A=\dfrac{x\left(x^2+3\right)-\left(x^2+3\right)}{x^3\left(x+3\right)+3\left(x+3\right)}=\dfrac{\left(x^2+3\right)\left(x-1\right)}{\left(x+3\right)\left(x^2+3\right)}\)
\(=\dfrac{x-1}{x+3}\)
2: A=-1
=>x-1=-x-3
=>2x=-2
=>x=-1(nhận)
3: Khi x=-2 thì \(A=\dfrac{-2-1}{-2+3}=-3\)
Câu 1:
a,MCD: R1//R2
\(R_{12}=\dfrac{R_1R_2}{R_1+R_2}=\dfrac{30\cdot20}{30+20}=12\left(\Omega\right)\)
b, MCD: R3nt(R1//R2)
\(R_{tđ}=R_3+R_{12}=30+12=42\left(\Omega\right)\)
Câu 2
a Điện trở và cường độ dòng điện tối đa mà biến trở đó có thể có
b,\(S=\dfrac{l\cdot\rho}{R}=\dfrac{100\cdot1,1\cdot10^{-6}}{200}=5,5\cdot10^{-7}\)
\(R=\sqrt{\dfrac{S}{\pi}}=\sqrt{\dfrac{5,5\cdot10^{-7}}{\pi}}=4,18\cdot10^{-4}\left(m\right)=0,418\left(mm\right)\)
5. The teacher advised Nam to do morning exercises regularly.
6. My mother told me to clean up the bedroom.
7. The doctor advised Lan not to eat too much meat.
8, My mother asked me to wait for her there.
9. Miss Jackson said Tim should work harder on English pronunciation.
10. The manager invited me to drink some coffee.
1.Lan asked me if i went to school by bike
2.They said that they wanted to meet Mr Nam the following week
3. Mrs Hoa asked Ba not to stay up too late
4.He told me to carry heavy bag for him
5. The doctor advised my father not to drink too much coffee in the evening