giải nhanh giúp mình với ạ mình cảm ơn trc
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a)
b) Vì đây là mạch điện gồm 2 đèn mắc nối tiếp nên:
U=U1+U2=2,4+2,5=4,9(V)
c) Vì đây là mạch điện gồm 2 đèn mắc nối tiếp nên:\
U=U1+U2 => U2 = U-U1=11,2-5,8=5,4(V)
d)
Vì đây là mạch điện gồm 2 đèn mắc nối tiếp nên:\
U=U1+U2 => U1 = U-U2=23,2-11,5=11,7(V)
V Transformation
1 In spite being quite poor, the villagers live a happy and healthy way
2 Despite studying very hard, he still didn't pass the exam
3 Although Sylvia had no interest in folklore, she still enjoyed the story
4 Despite having much experience in machinery, he didn't succeed in repairing this machine
5 Though it was dark, they continued to work
6 In spite of having health problems, he is always smiling
7 Despite the difficult exam, Kieu Anh got good marks
8 THe man about whom I told you works in the hospital
9 Do you know the girl to whom Tom is talking?
10 The tree which stankds near the gate of my house has lovely flowers
11 The book which I was reading yesterday was a lovely story
12 Do you know the new student whose name I can't remember?
13 I will never forget the day when I first met her
14 The country where I was born is beautiful
15 Because of the polluted water, it was unsafe to drink
16 Because he work hard and methodically, John succeeded in his exam
17 I suggest getting together and talking about our presentation before we do it in class
18 When did you built this stilt house?
19 If you don't hurry up, you will be late for school
20 You must turn off the TV before 11p.m
c) Ta có: \(\sqrt{\sqrt{x}+3}=3\)
\(\Leftrightarrow\sqrt{x}+3=9\)
\(\Leftrightarrow\sqrt{x}=6\)
hay x=36
Ta có: \(\sqrt{x-2\sqrt{x-1}}=2\)
\(\Leftrightarrow x-2\sqrt{x-1}-4=0\)
\(\Leftrightarrow x-1-2\cdot\sqrt{x-1}\cdot1+1=4\)
\(\Leftrightarrow\left(\sqrt{x-1}-1\right)^2=4\)
\(\Leftrightarrow\sqrt{x-1}-1=2\)
\(\Leftrightarrow\sqrt{x-1}=3\)
\(\Leftrightarrow x-1=9\)
hay x=10
Áp dụng công thức \(\left(\dfrac{1}{v}\right)'=\dfrac{-v'}{v^2}\)
Ta có \(y'=\dfrac{-\left(x^2+x-1\right)'}{\left(x^2+x-1\right)^2}=-\dfrac{\left(2x+1\right)}{\left(x^2+x-1\right)^2}\)
a: Xét ΔBAD có BA=BD
nên ΔBAD cân tại B
hay \(\widehat{BAD}=\widehat{BDA}\)
b: \(\widehat{HAD}+\widehat{BDA}=90^0\)
\(\widehat{CAD}+\widehat{BAD}=90^0\)
mà \(\widehat{BAD}=\widehat{BDA}\)
nên \(\widehat{HAD}=\widehat{CAD}\)
hay AD là tia phân giác của góc HAC
c: Xét ΔADH vuông tại H và ΔADK vuông tại K có
AD chung
\(\widehat{HAD}=\widehat{KAD}\)
Do đó:ΔADH=ΔADK
Suy ra: AH=AK
Câu 6: Để hàm số y=(1-m)x+3 nghịch biến trên R thì 1-m<0
=>m>1
=>Chọn B
Câu 7: D
Câu 10: (D)//(D')
=>\(\left\{{}\begin{matrix}3m+1=2\left(m+1\right)\\-2\ne-2\left(loại\right)\end{matrix}\right.\Leftrightarrow m\in\varnothing\)
=>Chọn D
Câu 11: \(x^2+2x+2=\left(x+1\right)^2+1>=1>0\forall x\)
=>\(\sqrt{x^2+2x+2}\) luôn xác định với mọi số thực x
=>Chọn A
Câu 12: Để hai đường thẳng y=x+3m+2 và y=3x+2m+3 cắt nhau tại một điểm trên trục tung thì \(\left\{{}\begin{matrix}1\ne3\left(đúng\right)\\3m+2=2m+3\end{matrix}\right.\)
=>3m+2=2m+3
=>m=1
=>Chọn C
2 Is your family with you hear
3 Does your wife enjoy athletics
4 Do you like life here in Italy?
5 Are you worried about the Italian Champion, Giacomo Zanetti
6 Dp you have any advice for young athletes