Cho mệnh đề: “x2 – 1 chia hết cho 24 khi và chỉ khi x là một số nguyên tố lớn hơn 3”.
Mệnh đề trên không thể viết lại thành mệnh đề nào sau đây?
Cho mệnh đề: “x2 – 1 chia hết cho 24 khi và chỉ khi x là một số nguyên tố lớn hơn 3”.
Mệnh đề trên không thể viết lại thành mệnh đề nào sau đây?
A. “x2 – 1 chia hết cho 24 tương đương với x là một số nguyên tố lớn hơn 3”;
B. “x2 – 1 chia hết cho 24 là điều kiện cần và đủ để x là một số nguyên tố lớn hơn 3”;
C. “x2 – 1 chia hết cho 24 nếu và chỉ nếu x là một số nguyên tố lớn hơn 3”;
D. “x2 – 1 chia hết cho 24 là điều kiện đủ để x là một số nguyên tố lớn hơn 3”
Hãy suy nghĩ và trả lời câu hỏi trước khi xem đáp án
- P tương đương với Q.
- P là điều kiện cần và đủ của Q.
- P nếu và chỉ nếu Q.
Câu hỏi liên quan
Cho tam giác ABC. Mệnh đề nào sau đây có mệnh đề đảo sai?
Read the following passage about Wildlife Conservation in Africa and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
Wildlife conservation in Africa is vital for preserving biodiversity and ensuring the survival of iconic species such as elephants, lions, and rhinos. [I] The continent is home to some of the world’s most diverse ecosystems, including savannahs, rainforests, and deserts. [II] Conservation efforts involve strategies like protecting habitats, combating poaching, and raising awareness about the importance of wildlife. [III] Despite challenges, success stories demonstrate the positive impact of these efforts. [IV]
One notable example comes from Kenya, where anti-poaching initiatives and community engagement have helped stabilize elephant populations in Amboseli National Park. Similarly, in South Africa, rhino conservation programs use advanced technologies like drones and GPS tracking to monitor and protect vulnerable animals. These efforts not only safeguard wildlife but also promote eco-tourism, which supports local economies.
However, wildlife conservation in Africa faces persistent threats. Habitat loss due to agricultural expansion and urbanization continues to endanger species. Climate change exacerbates these challenges, altering migration patterns and threatening ecosystems. Furthermore, poaching and the illegal wildlife trade remain significant concerns, driven by global demand for products such as ivory and rhino horn.
To overcome these challenges, conservationists emphasize the need for international collaboration and local community involvement. Initiatives like eco-tourism provide financial incentives for communities to protect wildlife. Governments, NGOs, and individuals must work together to ensure the survival of Africa’s unique species for future generations.
The word “these” in paragraph 2 refers to _____________.
Văn minh Ấn Độ cổ - trung đại gắn liền với những dòng sông nào?
Mark the letter A, B, C or D on your answer sheet to indicate the best arrangement of utterances or sentences to make a meaningful exchange or text in each of the following questions from 13 to 17.
Hi Alex,
a. I appreciate the recommendation for the language app—it’s been so helpful for my French practice.
b. Thanks for the podcast you suggested last week; it was really inspiring to listen to successful language learners share their tips.
c. By the way, have you ever considered joining an online language exchange group? I think it could be fun to try together.
d. I’ve been trying to set aside more time for speaking practice, but it’s a bit challenging with my busy schedule.
e. Still, I’m motivated to improve my French, and I’ll let you know if I find other useful resources.
Write back soon,
Jordan
Quốc hội có mấy chức năng chính?
Năng lượng của tụ điện được xác định bởi công nào nào sau đây?
Danh sách A sẽ như thế nào sau các lệnh sau?
>>> A = [2, 3, 5, 6]
>>> A. append(4)
>>> del (A[2])
Bước 1 của quy trình vẽ hình chiếu trục đo là gì?
Thị trường gạo, thị trường cà phê, thị trường thép thuộc cách phân loại nào của thị trường?
Xác định một từ / cụm từ SAI về ngữ pháp / hoặc ngữ nghĩa / logic / phong cách.
“Lễ nhận chức diễn ra vô cùng long trọng và đã thành công tốt đẹp.”
Cho cấu hình electron của nguyên tử nguyên tố X dưới dạng ô orbital như sau:
Điền thông tin còn thiếu để hoàn thành các phát biểu sau:
1. Số hiệu nguyên tử của X là . Nguyên tố X có tên gọi là và kí hiệu hoá học là .
2. Số electron độc thân trong nguyên tử X là .
3. Số electron lớp ngoài cùng của nguyên tử X là .
Ngành công nghiệp văn hóa nào sau đây cần thiết phải sử dụng chất liệu lịch sử trong quá trình phát triển?
Cho mệnh đề: "Nếu n là một số nguyên tố lớn 3 thì n2+20 là một hợp số". Mệnh đề nào sau đây tương đương với mệnh đề đã cho?
Cho tập hợp A = {x ∈ ℕ| 3 < 2x – 1 < m}.
Tìm giá trị của m để A là tập hợp rỗng?
Vì sao cần tiêu dùng hợp lí, có kế hoạch?
Read the following passage about lifelong learning and mark the letter A, B, C, or D on your answer sheet to indicate the best answer to each of the following questions from 31 to 40.
[I] Lifelong learning is the ongoing, voluntary, and self-motivated pursuit of knowledge for personal or professional development (Knowles, 2020). [II] This concept emphasizes that learning does not stop after formal education, but rather continues throughout an individual's life, adapting to changing circumstances and needs. [III] In today’s fast-paced world, where technology and job markets evolve rapidly, lifelong learning has become increasingly essential. [IV]
One of the primary benefits of lifelong learning is its ability to enhance employability. Individuals who engage in continuous education are more likely to keep their skills relevant and competitive in the job market. According to a report by the World Economic Forum (2021), over 50% of employees will need reskilling due to technological advancements in the coming years. Lifelong learners are better equipped to adapt to these changes, making them more attractive candidates for employers.
Moreover, lifelong learning contributes to personal fulfillment and mental well-being. Engaging in new learning experiences can stimulate the brain, foster creativity, and improve cognitive function. Research indicates that individuals who pursue learning opportunities throughout their lives tend to report higher levels of happiness and life satisfaction (Smith & Johnson, 2019). Whether it is taking a course, learning a new language, or picking up a new hobby, the process of acquiring knowledge can be enriching and enjoyable.
In addition, lifelong learning promotes social engagement and community involvement. Participating in educational programs or community workshops can foster connections with others who share similar interests. This social aspect of learning can enhance one's sense of belonging and support networks, which are crucial for mental health (Jones, 2022).
Overall, lifelong learning is not just an individual responsibility; it requires support from educational institutions, employers, and communities to create an environment conducive to continuous education. By fostering a culture of learning, society can better prepare individuals for the challenges of the future and ensure that everyone has the opportunity to thrive.
(Adapted from The Importance of Lifelong Learning by Knowles, Smith, Johnson, and others)
The word "enriching" in paragraph 3 is CLOSEST in meaning to ____.
Read the following passage about Building Understanding Across Nations and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.
In our interconnected world, cultural ambassadors play a vital role in bridging the gaps between different nations and peoples. These dedicated individuals and groups serve as links between cultures, fostering mutual understanding and respect through various activities and programs. Their mission is to showcase their own cultural heritage while learning about and appreciating others, creating pathways for meaningful dialogue and lasting connections across borders.
Cultural ambassadors employ numerous methods to achieve their goals. They organize traditional festivals and art exhibitions that display unique customs, allowing visitors to experience different cultures firsthand. Language exchange programs enable people to communicate more effectively, while cultural workshops teach traditional crafts, music, and dance. These ambassadors also utilize digital platforms to reach wider audiences, sharing stories and traditions through social media and online events that connect people from different corners of the world.
Despite their important work, cultural ambassadors face several challenges in their mission. Stereotypes and prejudices can create barriers to understanding, while language differences sometimes lead to misunderstandings. Limited resources and funding may restrict their activities, and political tensions between nations can complicate their efforts. However, these dedicated individuals persist in their work, believing that personal connections and shared experiences can overcome these obstacles and promote harmony among different communities.
Looking ahead, the role of cultural ambassadors becomes increasingly significant in our global society. Their efforts to build bridges between nations contribute to reducing conflicts and fostering peace. Through their continued dedication to promoting cross-cultural understanding, these ambassadors help create a more inclusive and connected world where differences are celebrated rather than feared. This ongoing process of cultural exchange remains essential for building a future based on mutual respect and cooperation.
In which paragraph does the writer mention what three methods are used by cultural ambassadors to achieve their goals?
Con người trong bài thơ hiện ra qua những hình ảnh nào?
- Cho \({\rm{f}}({\rm{x}})\) là hàm số liên tục trên \(\mathbb{R}.\) Phát biểu nào sau đây là đúng?
Phủ định mệnh đề Q: ''∀x∈R,x2−1>0'' là