GIÚP VỚI NHÁ
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 1)
\(\dfrac{9}{12}+\dfrac{10}{12}=\dfrac{12}{19}\)
\(\dfrac{50}{54}=\dfrac{27}{25}\)
\(\dfrac{16}{24}-\dfrac{9}{24}=\dfrac{7}{24}\)
\(\dfrac{8}{5}x\dfrac{4}{3}=\dfrac{32}{15}\)
____________________________________
Bài 2)
a) \(x=\dfrac{5}{2}-\dfrac{2}{7}\)
\(x=\dfrac{31}{14}\)
b) \(x=\dfrac{6}{7}x\dfrac{4}{5}\)
\(x=\dfrac{24}{35}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
will be used in the future
ours
interested in this film
of energy will be developed
will be found to reduce pollution in our city
to stay up late watching football matches last year
to be some trees in the field
excited about this story
energy will be used in the future
interested in this exercise
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{2}{3}\left(\dfrac{2}{10}+\dfrac{3}{10}+\dfrac{5}{10}\right)=\dfrac{2}{3}+\dfrac{10}{10}=\dfrac{2}{3}+1=\dfrac{5}{3}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Kết quả lần lượt là: 62,16% ; 10,81% ; 40,54% ; 51,35% ; 8,1%
Nhớ k cho mình nhé! ^-^
![](https://rs.olm.vn/images/avt/0.png?1311)
\(B=|2014-2x|+|2016-2x|\)
\(=|2014-2x|+|2x-2016|\ge|2014-2x+2x-2016|\)
Hay \(B\ge2\)
Dấu"="xảy ra \(\Leftrightarrow\left(2014-2x\right)\left(2x-2016\right)\ge0\)
\(\Leftrightarrow\hept{\begin{cases}2014-2x\ge0\\2x-2016\ge0\end{cases}}\)hoặc \(\hept{\begin{cases}2014-2x< 0\\2x-2016< 0\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}2x\le2014\\2x\ge2016\end{cases}\left(loai\right)}\)hoặc\(\hept{\begin{cases}2x>2014\\2x< 2016\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x>1007\\x< 1008\end{cases}}\)
\(\Leftrightarrow1007< x< 1008\)
Vậy \(B_{min}=2\)\(\Leftrightarrow1007< x< 1008\)
![](https://rs.olm.vn/images/avt/0.png?1311)
Bài 6:
a: Ta có: \(E=1:\left(\dfrac{x^2+2}{x^3-1}-\dfrac{x+1}{x^2+x+1}-\dfrac{x+1}{x^2-1}\right)\)
\(=1:\left(\dfrac{x^2+2}{\left(x-1\right)\left(x^2+x+1\right)}-\dfrac{x+1}{x^2+x+1}-\dfrac{1}{x-1}\right)\)
\(=1:\dfrac{x^2+2-x^2+1-x^2-x-1}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(=\dfrac{\left(x-1\right)\left(x^2+x+1\right)}{-x^2-x+2}\)
\(=\dfrac{-\left(x-1\right)\left(x^2+x+1\right)}{\left(x+2\right)\left(x-1\right)}\)
\(=\dfrac{-x^2-x-1}{x+2}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(2/\\ Fe_2O_3 + 3H_2SO_4 \to Fe_2(SO_4)_3 + 3H_2O\\ Al_2O_3 + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2O\\ MgO + H_2SO_4 \to MgSO_4 + H_2O\\ Na_2O + H_2SO_4 \to Na_2SO_4 + H_2O\\ n_{H_2O} = n_{H_2SO_4} = \dfrac{41,16}{98}=0,42(mol)\\ m_{hh} + m_{axit} = m_{Muối} + m_{H_2O} \\ \Rightarrow m_{muối} = 20,66 + 41,16 -0,42.18 = 54,26(gam)\)
![](https://rs.olm.vn/images/avt/0.png?1311)
4:
=145(69+22+8+1)
=145*100=14500
3:
Xe 1 chở: (168+26):2=194:2=97 tạ
Xe 2 chở 97-26=71 tạ
A nhé bạn!
Vì 15\(\frac{2}{5}\)dm= 15\(\frac{4}{10}\)dm= 15,4 dm= 154 cm
10 m 24 cm= 1024 cm
Chiều rộng là: (1024-154):2=435 (cm)
Chiều dài là: 1024-435= 589 (cm)
Diện tích HCN đó là:
589x435= 256215 (cm2)
Đáp số: 256215 cm2.
tổng hiệu bình thường thôi bn, đổi hỗn số ra phân số rồi giải theo cách tổng hiệu
hoc tốt