![](https://rs.olm.vn/images/background/bg0.jpg?v=2)
![](https://rs.olm.vn/images/avt/1.png?13)
Nguyễn Thị Ái Vân
Giới thiệu về bản thân
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_mam_non.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_tan_binh.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_chuyen_can.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_cao_thu.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_thong_thai.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_kien_tuong.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
![xếp hạng xếp hạng](https://rs.olm.vn/images/medal_dai_kien_tuong.png)
![ngôi sao 1 Ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 2 ngôi sao 2](https://rs.olm.vn/images/medal_ngoi_sao.png)
![ngôi sao 3 ngôi sao 1](https://rs.olm.vn/images/medal_ngoi_sao.png)
![sao chiến thắng Sao chiến thắng](https://rs.olm.vn/images/medal_win_1.png)
\(x^8-x^7+x^2-x+1>0\)
<=> \(x\left(x-1\right)\left(x^6+1\right)+1>0\)
<=> \(x\left(x-1\right)\left(x^6+1\right)>-1\)
<=>\(\left[{}\begin{matrix}x>-1\\x-1>-1\\x^6+1>-1\end{matrix}\right.\)
<=> \(\left[{}\begin{matrix}x>-1\\x>0\\x^6>-2\end{matrix}\right.\)
<=> \(\left[{}\begin{matrix}x>-1\\x>0\\x\in R\end{matrix}\right.\)
Xét từng trường hợp:
x > -1 (loại). Vì không thỏa mãn điều kiện.
x > 0 (loại). Vì không thỏa mãn điều kiện.
x ϵ R (nhận). Vì thỏa mãn điều kiện (đpcm)
A community helper I admire is a doctor. Physicians and surgeons diagnose and treat injuries or illnesses and address health maintenance. Physicians examine patients; take medical histories; prescribe medications; and order, perform, and interpret diagnostic tests. They often counsel patients on diet, hygiene, and preventive healthcare. I feel grateful for doctors because they help us grow and healthy every day.
a/ \(\dfrac{8\sqrt{2}-\sqrt{32}-4}{1-\sqrt{2}}\)
= \(\dfrac{-4\left(2\sqrt{2}-\sqrt{2}-1\right)}{1-\sqrt{2}}\)
= \(\dfrac{-4\left(1-\sqrt{2}\right)}{1-\sqrt{2}}\)
= -4
b/ ĐKXĐ: \(\left\{{}\begin{matrix}x\ge0\\x-4\ne0\\\sqrt{x}+2\ne0\\\sqrt{x}-2\ne0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x\ge0\\x\ne4\end{matrix}\right.\)
Đổi: 20 phút = \(\dfrac{1}{3}giờ\)
Gọi s (km) là quãng đường từ thành phố về quê (s > 0).
Thời gian từ thành phố về quê là: \(\dfrac{s}{30}+\dfrac{1}{3}\) (giờ)
Thời gian từ quê lên thành phố là: \(\dfrac{s}{25}\) (giờ)
Ta có phương trình:
\(\dfrac{s}{25}\)= \(\dfrac{s}{30}+\dfrac{1}{3}\)
\(\dfrac{6s}{25.6}\)=\(\dfrac{5s}{30.5}+\dfrac{50}{3.50}\)
6s = 5s + 50
6s - 5s = 50
s = 50 (nhận)
Vậy quãng đường từ thành phố về quê là 50 km.
a/ 3x - 5 = 4 b/ \(\dfrac{2x}{3}+\dfrac{3x-1}{6}=\dfrac{x}{2}\)
3x = 4 + 5 \(\dfrac{2x.2}{3.2}+\dfrac{3x-1}{6}=\dfrac{x.3}{2.3}\)
3x = 9
x = \(\dfrac{9}{3}=3\) 4x + 3x - 1 = 3x
Vậy: S = {3} 7x - 1 = 3x
7x - 3x = 1
4x = 1
x = \(\dfrac{1}{4}\)
Vậy: S = {\(\dfrac{1}{4}\)}
a/ 3x - 4 = 5 + x
3x - x = 5 + 4
2x = 9
x = \(\dfrac{9}{2}\)
Vậy: S = {\(\dfrac{9}{2}\)}
b/ 3(x - 1) - 7 = 5(x + 2)
3x - 3 - 7 = 5x + 10
3x - 10 = 5x + 10
(-10) - 10 = 5x - 3x
-20 = 2x
x = \(\dfrac{-20}{2}\)
x = -10
Vậy: S = {-10}
The regulation to prohibit mobile phones in secondary schools is a topic of considerable debate. On one hand, mobile phones can be a significant distraction, potentially disrupting the learning environment and facilitating cheating. They can also contribute to social issues, such as cyberbullying. On the other hand, mobile phones are powerful tools for learning and communication, providing students with access to educational resources and a means to contact family in emergencies. Ultimately, the effectiveness of such a regulation depends on its implementation and the school’s ability to provide alternative resources. A balanced approach, where mobile phone use is regulated rather than completely banned, might serve to mitigate the drawbacks while still harnessing the benefits of technology in education.