M.n giúp mình với nào, bài dài quá
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1, chỉ cách làm mẫu nek:
NO+O2=>NO2
NO+O2 là vế 1, NO2 là vế 2
vế 1 : N=1, O=3
vế 2 : N=1, O=2
cân bằng:
vế 2: 2O2( O vế 2 ít ng tử hơn )
lúc này vế 2 có O=4 vàN=2
vế 1: 2NO
lúc này vế 1 N=2, O=4
kl : 2NO+O2=>2NO2
2 , làm y như nãy:
4P+5O2=>2P2O5
3, Fe2O3+3H2SO4=>Fe(SO4)3+3H2O
để\(\frac{2x-1}{3+x}\Leftrightarrow\orbr{\begin{cases}\hept{\begin{cases}2x-1< 0\\3+x>0\end{cases}}\\\hept{\begin{cases}2x-1>0\\3+x< 0\end{cases}}\end{cases}}\Leftrightarrow\orbr{\begin{cases}\hept{\begin{cases}x< \frac{1}{2}\\x>-3\end{cases}\left(ktm\right)}\\\hept{\begin{cases}x>\frac{1}{2}\\x< -3\end{cases}\left(tm\right)}\end{cases}}\)
Vậy -3<x<1/2
1, set about: attack someone
2, call back: return to see or collect sth
3, pay me back: return money to someone you borrow
4, go right back to: kiểu nó bắt đầu từ thời Trung Cổ ấy
5, look after: chắc cái này bạn biết nhỉ
6, set about: start doing something
7, turn back: return
8, went about: begin to do something or deal with something
9, called me back: telephone someone again
10, holding back: stating sth
Bài 3:
Chiều rộng là:
\(\dfrac{11}{4}-\dfrac{3}{2}=\dfrac{11}{4}-\dfrac{6}{4}=\dfrac{5}{4}\left(m\right)\)
Chu vi là:
\(\left(\dfrac{11}{4}+\dfrac{5}{4}\right)\cdot2=\dfrac{16}{4}\cdot2=4\cdot2=8\left(m\right)\)
Diện tích là:
\(\dfrac{11}{4}\cdot\dfrac{5}{4}=\dfrac{55}{16}\left(m^2\right)\)
Giúp mình viết 1 bài speaking chủ đề My hobbies is playing video games với tầm 3 4 đoạn đừng quá dài
I find playing online games very interesting. It can support me to feel relaxative after everyday after tired time of learning at school. I usually to play online chess. It is exciting and challenging. It also help me to make friends online. It helps me to think over everything before acting. However, I always limit my time of playing online games. Because I think playing too much online games makes me tired. My eyes are often soring. My mother always reminds me of learning hard, so I know what is the most important to me. Playing online games only helps me to relax a little. So I advise you to working hard at school, and just spend a little time playing online games, although how much you it.
Watching television is one of the activities I like to do in my spare time. I enjoy watching cartoons on Saturday mornings and sports programs on Sunday afternoons. I also watch television during the week after I have finished all my school work. At night, I especially like to watch movies and situation comedies. If I have a lot of homework, I try to arrange my schedule so that I can watch at least one of my favorite shows. Watching television is not the only activity that I do in my spare time. My other favorite activities are making paper flowers and going shopping with my friends. However, when I have spare time, I spend more time watching television than any other activities. Watching television can help me not only relax but also build me a huge knowledge of the open world.”
---------------
Check it out ~ MDia