M.N giúp mk lên 120sp nha
MK cảm ơn M.N nhiều lắm ạ!!!
5.5
6.6
7.7
8.8
9.9
10.10
Mong m.n giúp mk nha. Cảm ơn m.n chước ạ <3
Giải giúp mk phương trình này vs m.n ơi
X/2x-3 + x/x-2 = 2x/(x+1)(x-3)
Mik cần gấp lắm m.n giải giúp ạ cảm ơn nhiều
M.n xin giúp em câu 23 ạ,em nghĩ mãi mà ko ra,xin m.n giúp em ,em cảm ơn rất nhiều ạ!!!!
Vận tốc của chất điểm:
\(v\left(t\right)=s'\left(t\right)=3t^2-6t+9=3\left(t-1\right)^2+6\ge6\)
Dấu "=" xảy ra khi \(t-1=0\Rightarrow t=1s\)
47.3=???
55.11=???
77.2-154=???
Giúp mk lên 130sp nha cảm ơn M.N nhiều
Nhứ tick lại mk nha
47 . 3 = 141
55 . 11 = 605
77 . 2 - 154 = 0
T.i.c.k mình nha.MÌnh rùi đó.
M.n giúp mik với ạ cảm ơn nhiều ;-;
a)
\(n_{Fe_2O_3}=\dfrac{24}{160}=0,15\left(mol\right)\\ n_{H_2SO_4}=0,2.2,5=0,5\left(mol\right)\\ PTHH:Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O.\\ Vì:\dfrac{0,15}{1}< \dfrac{0,5}{3}\)
=> H2SO4 dư, Fe2O3 hết => Tính theo Fe2O3
Ta có:
\(n_{H_2SO_4\left(dư\right)}=0,5-\left(0,15.3\right)=0,05\left(mol\right)\\ \Rightarrow m_{H_2SO_4\left(dư\right)}=0,05.98=4,9\left(g\right)\)
b) \(n_{Fe_2\left(SO_4\right)_3}=n_{Fe_2O_3}=0,15\left(mol\right)\)
=> \(m_{Fe_2\left(SO_4\right)_3}=0,15.400=60\left(g\right)\)
c) \(V_{ddFe_2\left(SO_4\right)_3}=V_{ddH_2SO_4}=200\left(ml\right)=0,2\left(l\right)\)
Vậy: \(C_{MddFe_2\left(SO_4\right)_3}=\dfrac{0,15}{0,2}=0,75\left(M\right)\)
nFe2O3= 24/160 = 0,15 mol
nH2SO4 = 0,2.2,5= 0,5 mol
Fe2O3 + 3H2SO4 -> Fe2(SO4)3 + 3H2O
0,15 0,5
ta có 0,15/1 < 0,5/3
=> H2SO4 dư
Fe2O3 +3H2SO4 -> Fe2(SO4)3 +3H2O
0,15 0,45 0,15
nH2SO4 dư = 0,5-0,45=0,05mol
mH2SO4 dư = 05.98=4,9(g)
b, mFe2(SO4)3 = 0,15.400=60(g)
c, C(Fe2(SO4)3) = n/V = 0,15/ 0,2=0,75M
C(H2SO4) dư = n/V = 0,05/0,2= 0,25 M
Sau khi làm thí nghiệm khí SO2 dư được hấp thụ bằng dung dịch Ca(OH)2. Tính khối lượng Ca(OH)2 cần dùng để hấp thụ hoàn toàn 5,6 lít khí SO2 ở đktc.
(m.n giúp mik vs ạ. Mik cảm ơn m.n nhiều lắm)
Giúp mk vs cảm ơn M.n ạ
Câu 9: B
Câu 10: B
Câu 11: A
Câu 12: D
Câu 13: C
Câu 14: A
Câu 15: C
Write a paragraph of 70 words about crime in the city
(m.n giúp mik vs ạ. Cảm ơn m.n nhiều)
Tham khảo!
There are many advantages and disadvantages of choosing to live in the country or to live in the city. But the advantages of living in the country definitely outweigh the advantages of living in the city.
In the city, public schools are often packed full of students resulting in larger class sizes and no real teacher student relationship. You would be lucky if your teacher could put a name to your face. Though, bigger schools in the city offer more courses for the student to take and also offer more extracurricular activities. Where in the country, public schools often do not have many students making class sizes significantly smaller resulting in a better teacher student relationship. Your teacher usually knows you by first and last name, and chances are, your teacher had a few of your family members as students. Though these things are advantages, school in rural areas generally do not offer as many courses and also do not have as many extracurricular activities to be involved in, limiting the students to fewer opportunities.
There are a lot of activities to do in the city. There are more movie theaters, concerts, professional sporting events, zoos, shopping malls, restaurants and museums. But the activities you can do in the country are a lot more fun. In the country, activities consist of, four wheeling, boating, horseback riding, camping, having bon fires, taking walks in the woods and having back yard barbeques.
Transportation is very accessible in the city. Public transportation, by way of subways, busses, trams and ferries are easy and cheap ways of getting around. But the streets are also very crowded. Whereas owning your own vehicle is a must if you live in the country. Which, when added to the cost of insurance, gas and the time of commuting, can end up being a very large expense. But, with the roads being less crowded, it is a much more peaceful way to travel.
Some may believe that you have to...
x2 + 4x + 3
mọi người tính hộ mk với ạ mai mk thi rồi ạ !
cảm ơn m.n nhiều !
\(x^2+4x+3=x^2+3x+x+3=\left(x^2+3x\right)+\left(x+3\right)=x\left(x+3\right)+\left(x+3\right)=\left(x+3\right)\left(x+1\right)\)
m.n giúp mk câu này vs ạ
(\(\dfrac{x+2}{x-2}-\dfrac{x-2}{x+2}+\dfrac{16}{4-x^2}\)) : (\(\dfrac{4}{2-x}-\dfrac{8}{2x-x^2}\))