Để biểu diễn miền nghiệm của bất phương trình bậc nhất hai ẩn 2x + y – 4 > 0, bạn An đã làm theo 3 bước:
Bước 1: Trên mặt phẳng tọa độ Oxy, vẽ đường thẳng ∆: 2x + y – 4 = 0.
Bước 2: Lấy một điểm (0; 0) không thuộc ∆. Tính 2. 0 + 0 – 4 = ‒ 4.
Bước 3: Kết luận:
Do ‒4 < 0 nên miền nghiệm của bất phương trình đã cho là nửa mặt phẳng (không kể bờ ∆) chứa điểm (0; 0).
Bước 4: Biểu diễn miền nghiệm trên trục tọa độ Oxy:
Cô giáo kiểm tra bài bạn An và nói rằng bài bạn làm sai. Bạn An đã làm sai từ bước nào?
Câu hỏi liên quan
Việc Nhà nước có biện pháp để mở rộng quy mô và chất lượng các trường dạy nghề là góp phần thực hiện chính sách an sinh xã hội nào dưới đây?
Chọn khẳng định sai trong các khẳng định sau:
Ở Cá xương, mỗi mang có mấy cung mang?
Giống cây trồng:Cho hàm số có đồ thị là đường cong như hình vẽ:
Hàm số đã cho nghịch biến trên khoảng nào dưới đây?
Biết rằng mùi tanh của cá (đặc biệt là cá mè) là hỗn hợp các amine và một số chất khác. Để khử mùi tanh của các trước khi nấu chúng ta có thể sử dụng dung dịch chất nào dưới đây?
Hoạ sĩ thiết kế một micro có dạng khối tròn xoay, mặt cắt đứng chứa trục của khối tròn xoay có dạng như hình sau, trong đó \({\rm{OA}} = {\rm{OB}} = {\rm{OI}} = 2\;{\rm{cm}}\), \({\rm{MC}} = {\rm{MD}} = 1\;{\rm{cm}}\), đường thẳng OM là đường trung trực của đoạn thẳng CD, \({\rm{OM}} = 20\;{\rm{cm}},\widehat {{\rm{AOB}}} = {90^o }.\) Thể tích của micro này là bao nhiêu \({\rm{c}}{{\rm{m}}^3}\) ? (Làm tròn kết quả đến hàng đơn vị)
Read the following passage about the Pathways from Today's Actions to Tomorrow's World 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.
As we stand at the crossroads of environmental decision-making, the actions we take today will shape our world in 2050. Scientists warn that we're skating on thin ice with current consumption patterns and carbon emissions. Global temperatures could rise by 2-4 degrees Celsius unless significant changes occur within the next decade. Many countries have pledged to achieve carbon neutrality by 2050, but these promises require immediate implementation. Individual choices in transportation, energy usage, and consumption can collectively influence whether future generations inherit a sustainable planet or face severe climate consequences.
[I] Technological innovation represents our greatest hope for addressing environmental challenges by 2050. [II] Renewable energy sources like solar and wind are becoming increasingly affordable, potentially replacing fossil fuels entirely within thirty years. [III] Electric vehicles may dominate transportation networks, while vertical farming could transform food production in urban areas. [IV] However, these technological solutions must be developed and deployed equitably to avoid creating new disparities between wealthy and developing nations.
Social structures will undergo dramatic transformation by 2050 as demographic shifts reshape communities worldwide. Aging populations in developed countries will necessitate new approaches to healthcare, retirement, and social support systems. Meanwhile, climate migration may force millions to relocate from vulnerable coastal and drought-prone regions. Education systems must evolve to prepare our students for jobs that don't yet exist, emphasizing their adaptability and lifelong learning. Cities will need to become more resilient, incorporating green spaces and sustainable infrastructure to support growing populations.
Economic models must fundamentally change by 2050 to balance prosperity with environmental responsibility. The traditional focus on continuous growth may shift toward measuring success through wellbeing indicators rather than GDP alone. Circular economy principles will likely replace linear production models, with products designed for reuse and recycling. Resource-sharing platforms may become more prevalent, reducing individual consumption while maintaining living standards. Companies implementing genuinely sustainable practices will thrive, while those clinging to environmentally harmful methods may disappear entirely. The transition presents both challenges and opportunities for businesses willing to embrace innovation and sustainability.
Which of the following is NOT mentioned as a potential change by 2050?
Đánh giá công nghệ có vai trò nào sau đây trong lựa chọn thiết bị?
Diện tích gieo trồng lúa của nước ta giảm là do
Read the following passage about the Pathways from Today's Actions to Tomorrow's World 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.
As we stand at the crossroads of environmental decision-making, the actions we take today will shape our world in 2050. Scientists warn that we're skating on thin ice with current consumption patterns and carbon emissions. Global temperatures could rise by 2-4 degrees Celsius unless significant changes occur within the next decade. Many countries have pledged to achieve carbon neutrality by 2050, but these promises require immediate implementation. Individual choices in transportation, energy usage, and consumption can collectively influence whether future generations inherit a sustainable planet or face severe climate consequences.
[I] Technological innovation represents our greatest hope for addressing environmental challenges by 2050. [II] Renewable energy sources like solar and wind are becoming increasingly affordable, potentially replacing fossil fuels entirely within thirty years. [III] Electric vehicles may dominate transportation networks, while vertical farming could transform food production in urban areas. [IV] However, these technological solutions must be developed and deployed equitably to avoid creating new disparities between wealthy and developing nations.
Social structures will undergo dramatic transformation by 2050 as demographic shifts reshape communities worldwide. Aging populations in developed countries will necessitate new approaches to healthcare, retirement, and social support systems. Meanwhile, climate migration may force millions to relocate from vulnerable coastal and drought-prone regions. Education systems must evolve to prepare our students for jobs that don't yet exist, emphasizing their adaptability and lifelong learning. Cities will need to become more resilient, incorporating green spaces and sustainable infrastructure to support growing populations.
Economic models must fundamentally change by 2050 to balance prosperity with environmental responsibility. The traditional focus on continuous growth may shift toward measuring success through wellbeing indicators rather than GDP alone. Circular economy principles will likely replace linear production models, with products designed for reuse and recycling. Resource-sharing platforms may become more prevalent, reducing individual consumption while maintaining living standards. Companies implementing genuinely sustainable practices will thrive, while those clinging to environmentally harmful methods may disappear entirely. The transition presents both challenges and opportunities for businesses willing to embrace innovation and sustainability.
The word “necessitate” in paragraph 3 is OPPOSITE in meaning to _________.
- Kim loại cơ bản trong dural là
Tốc độ sóng là
Trong kĩ thuật chuyển gene có bước nào sau đây?
Nguyên tử X có 3 lớp electron, lớp thứ 3 chứa 4 electron. Số hiệu nguyên tử của X là
Đối với các hành vi vi phạm quyền bất khả xâm phạm về chỗ ở của công dân, chúng ta cần
Công nghệ khử nước được ứng dụng cho bảo quản
- Để tiết kiệm điện khi sử dụng bình nước nóng, cần điều chỉnh nhiệt độ
Read the following leaflet and mark the letter A, B, C, or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 7 to 12.
STAY SAFE: UNDERSTANDING SCAMS AND HOW TO PREVENT THEM
What is a scam?
A scam is a deceptive scheme delivered through digital communications with the intent to steal money or personal information. These schemes take many forms, including online fraud, phishing emails, and fake lotteries. In (7) _____ words, scams are tricks that prey on your trust and can lead to significant financial loss.
Common types of scams
- Phishing: fraudulent emails or messages that appear to be from legitimate sources, tricking you into (8) _____ personal information.
- Lottery scams: notifications claiming you’ve won a (9) _____, requiring you to pay a fee to claim it.
- Other scams: these can include fake charities, advance-fee scams, and online auction fraud, each designed to exploit individuals in different ways.
Tips to prevent scams
- Verify sources: always check the (10) ____ of requestions for personal information.
- Root out suspicious communications: don’t engage with unknown contacts and report any suspicious emails or calls to the authorities (11) _____ potential scams.
- Protect your information: use strong passwords and enable two-factor authentication on your accounts to add an extra (12) ______ of security.
- Tập nghiệm của bất phương trình \({\left( {\frac{3}{4}} \right)^{2x - 1}} \le {\left( {\frac{4}{3}} \right)^{ - 2 + x}}\) là:
