giúp vs nha mn
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2 she had got the price of the contest, she would be happy now
3 I had gone to the concert last night ,I would be tired
4 John had finished all his homework, he could see a movie now
5 we had listened to my mother, we wouldn't be in trouble right now
Ex5
1 you arrive at the offcie earlier than I do, please turn on the air-conditioner
2 Were it not snowy, the children would go to school
3 he not died so young, he would be a famous musician
4 Were I you, I would take care of my car
5 not very bad-tempered, his wife would give him soon are marrage
6 Had she not got married at such an early age, he would be at university
1, I'm so ............excited..... about your trip . It's going to be amazing ( excite )
2, Ao Dai is us=> our ..........traditional......... dress . We wear it every Monday at school ( tradition )
3, In Vietnam , we usually wait for the ...............elderly..... person to sit down before you sit down ( old )
4, After .............taking..... food from the plate you should put it into your bowl before eating ( take )
5, What is the ..........similarity.......between a custom and a tradition ( similer)
\(P=\dfrac{1}{1.2}+\dfrac{1}{2.3}+\dfrac{1}{3.4}+...+\dfrac{1}{99.100}\)
\(=\dfrac{1}{1}-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{99}-\dfrac{1}{100}\)
\(=1-\dfrac{1}{100}=\dfrac{99}{100}\)
P=1-1/2+1/2-1/3+1/3-1/4+...+1/99-1/100
=1+(1/2-1/2)+(1/3-1/3)+...+(1/99-1/99)-1/100
=1+0+0+0+...+0-1/100
=1-100
=100/100-1/100
=99/100
c: \(=\left(157-81\right):4-3^3=19-27=-8\)
d: \(=250:\left\{5\cdot\left[88\cdot1-2024+1946\right]\right\}=250:50=5\)
\(n_{CuSO_4}=0,2x\left(mol\right)\)
\(Fe+CuSO_4\rightarrow FeSO_4+Cu\)
0,2x 0,2x 0,2x
\(m_{tăng}=m_{Cu}-m_{Fe}=64\cdot0,2x-56\cdot0,2x=1,6\)
\(\Rightarrow x=1M\)
Chọn C.
\(n_{Fe}=n_{FeSO_4}=n_{Cu}=n_{CuSO_4}=0,2.x\left(mol\right)\\ Fe+CuSO_4\rightarrow FeSO_4+Cu\\ m_{t\text{ăn}g}=m_{Cu.b\text{á}m.v\text{ào}}-m_{Fe.tan.ra}\\ \Leftrightarrow1,6=64.0,2x-56.0,2x\\ \Leftrightarrow x=1\\ \Rightarrow C\)
bạn ơi, bạn chia nhỏ ra để hỏi nha! Vì các bài sau đây để làm hết trình bày sẽ lâu lắm ah!
câu 17
Lập công thức hóa học của hợp chất; \(Cu_x\)\(S_y\)\(O_z\)
Khối lượng phân tử của hợp chất; 64.x+32.y+16.z = 160 amu
Lập công thức để tìm x,y,z
%O trong hợp chất là; O= 100-(40+20)=> 40%
Cu= \(\dfrac{64.x.100\%}{160}\)=40% => x = \(\dfrac{160.40\%}{64.100}\)=1 amu
S= \(\dfrac{32.y.100\%}{160}\)=20% => y = \(\dfrac{160.20\%}{32.100}\)=1 amu
O= \(\dfrac{16.x.100\%}{160}\)=40% => z = \(\dfrac{160.40\%}{16.100}\)= 4 amu
Công thức hóa học của hợp chất là \(CuSO_4\)
\(P=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{99}-\dfrac{1}{100}=1-\dfrac{1}{100}=\dfrac{99}{100}\)
Ta có :
\(P=\frac{1}{1.2}\)\(+\frac{1}{2.3}\)\(+\frac{1}{3.4}\)\(+.......+\frac{1}{99.100}\)
\(P=1-\frac{1}{2}\)\(+\frac{1}{2}\)\(-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+......+\frac{1}{98}-\frac{1}{99}-\frac{1}{100}\)
\(P=1-\frac{1}{100}\)
\(P=\frac{99}{100}\)