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NH
3
YN
28 tháng 12 2021
Answer:
a) 42% của 60kg
\(60\times42:100=25,2kg\)
b) 36,5% của 2ha
\(2\times36,5:100=0,73ha\)
CT
28 tháng 12 2021
TL:
Bài 1
a) 42% của 60 kg là :
60 : 100 x 42 = 25,2 kg
b) 36,5% của 2 ha là :
2 : 100 x 36,5 = 0,73 ha
giúp mk với ak
DT
Đỗ Thanh Hải
CTVVIP
30 tháng 6 2021
1 to work by car every morning
2 there 25 students in your class
3 quater past seven
4 is to the left of the drug store
5 small classroom
6 your school have
7 longer than the red river
30 tháng 6 2021
1. to work by car every morning
2 .there 25 students in your class
3 .quater past seven
4 .is to the left of the drug store
5. small classroom
6 .your school have
7 .longer than the red river
R
6 tháng 11 2021
a)\(\dfrac{87}{5}\)
b)\(6\)
c)\(\dfrac{224}{3}\)
d)\(\dfrac{31}{4}\)
19 tháng 10 2021
1, The last shirt of this style was sold a few hours ago
2,,The Eiffiel was built in 1889
3,Rice is grown in tropical countries
4, This room is cleaned everyday
5, Our hands ,ust be washed before meal
6, You will be told what time the train leave by ur sis
7,A new bridge is going to be built in this area
8, He homework hasn't been done by her yet
9, Some friends of her have been asked to join us
11, I wish I knew many English words
12, I wish my friend could stay with me longer
13, I wish Lan were here
14, I wish I had a pen pal
15, I wish I could go to the soccer match that afternoon
16, She wishes she could speak English
DT
Đỗ Thanh Hải
CTVVIP
10 tháng 8 2021
1 saw - didn't see - was looking
2 met - went - went - had - were waiting
3 was cycling - stepped - was going - managed - didn't hit
4 was waiting - arrived
5 were you doing
6 Did you go
7 wore
8 were you driving - happened
9 took - wasn't looking
10 were - didn't know
NV
Nguyễn Việt Lâm
Giáo viên
6 tháng 9 2021
Bài 1:
ĐKXĐ:
a. \(sinx\ne0\Rightarrow x\ne k\pi\)
b. \(sin2x\ne0\Rightarrow2x\ne k\pi\Rightarrow x\ne\dfrac{k\pi}{2}\)
c. \(cosx\ne0\Rightarrow x\ne\dfrac{\pi}{2}+k\pi\)
d. \(cos\left(x+\dfrac{\pi}{4}\right)\ne0\Rightarrow x+\dfrac{\pi}{4}\ne\dfrac{\pi}{2}+k\pi\Rightarrow x\ne\dfrac{\pi}{4}+k\pi\)
e. \(cos2x\ne0\Rightarrow2x\ne\dfrac{\pi}{2}+k\pi\Rightarrow x\ne\dfrac{\pi}{4}+\dfrac{k\pi}{2}\)
f. \(sin\left(x-\dfrac{\pi}{3}\right)\ne0\Rightarrow x-\dfrac{\pi}{3}\ne k\pi\Rightarrow x\ne\dfrac{\pi}{3}+k\pi\)
g. \(sinx+1\ge0\Rightarrow D=R\)
h. \(cosx-2\ne0\Rightarrow D=R\)
i. \(cosx-1\ne0\Rightarrow cosx\ne1\Rightarrow x\ne k2\pi\)
NV
Nguyễn Việt Lâm
Giáo viên
6 tháng 9 2021
Bài 2:
a.
\(-1\le cosx\le1\Rightarrow-3\le3cosx\le3\Rightarrow-4\le y\le2\)
\(y_{min}=-4\) khi \(cosx=-1\)
\(y_{max}=2\) khi \(cosx=1\)
b.
\(-1\le sinx\le1\Rightarrow-1\le-sinx\le1\) \(\Rightarrow4\le y\le6\)
\(y_{min}=4\) khi \(sinx=1\)
\(y_{max}=6\) khi \(cosx=1\)
c.
\(0\le\sqrt{cosx}\le1\Rightarrow-3\le y\le-2\)
\(y_{min}=-3\) khi \(cosx=0\)
\(y_{max}=-2\) khi \(cosx=1\)
d.
\(0\le sin^2x\le1\Rightarrow2\le y\le3\)
\(y_{min}=2\) khi \(sinx=0\)
\(y_{max}=3\) khi \(sin^2x=1\Leftrightarrow cosx=0\)
HB
0
DT
Đỗ Thanh Hải
CTVVIP
13 tháng 4 2021
1 2H2S + 3O2 \(\xrightarrow[]{t^o}\) 2SO2 + 2H2O
2 2H2O + 2KMnO4 + 5SO2 \(\xrightarrow[]{t^o}\) 2H2SO4 + 2MnSO4 + K2SO4
3 H2SO4 + Na2SO3 \(\rightarrow\) H2O + Na2SO4 + SO2
4 2C + SO2 \(\xrightarrow[]{t^o}\) 2CO + S
5 Fe + S \(\xrightarrow[]{t^o}\) FeS
6 H2SO4 +NaCl \(\rightarrow\) NaHSO4 + HCl
7 K2CO3 + 2NaHSO4 \(\rightarrow\) H2O + Na2SO4 + K2SO4+CO2
8 Na2SO4 + Ba(OH)2 \(\rightarrow\) 2NaOH + BaSO4
9 Br2 + H2O +SO2 \(\rightarrow\) H2SO4 + 2HBr
10 2HBr + Cl2 \(\rightarrow\) Br2 + 2HCl
21 tháng 5 2021
I.
1D 2C 3A
II.
4D 5A 6C
III.
7B 8A 9A 10D 11D 12C 13C 14C 15A
IV.
16 explorer
17 dramatically
18 survival
19 challenging
20 unconscious
V.
21D 22B 23A 24C 25A
43. Not to spend so much money on magazines
44. Don't have to take part in the festival if you don't want to.
45. Was able to ride a bike when she was 5.
a. \(Ba\left(OH\right)_2+H_2SO_4\rightarrow BaSO_4+2H_2O\)
b. \(m_{ddH_2SO_4}=1,2.100=120g\)
\(n_{H_2SO_4}=\frac{120.19,6\%}{98}=0,24mol\)
\(n_{Ba\left(OH\right)_2}=n_{H_2SO_4}=0,24mol\)
\(m_{ddBa\left(OH\right)_2}=\frac{0,24.171}{20\%}=205,2g\)
c. \(n_{BaSO_4}=n_{H_2SO_4}=0,24mol\)
\(m_{BaSO_4}=233.0,24=55,92g\)