Cho hệ phương trình
Cặp số (x ; y) là nghiệm của hệ phương trình:
A. B. C. D.
Lưu ý: Bạn hãy đăng nhập để lưu lại lịch sử làm bài của mình
Hôm nay, bạn còn lượt làm bài tập.
Đua top nhận quà tháng 4/2022Đại sứ văn hoá đọc 2022 Đặt câu hỏi Cặp số là nghiệm của bất phương trình nào sau đây?
A..
B..
C.x+3y+1 < 0
D..
Đáp án và lời giải
Đáp án:C
Lời giải: Chọn C Thaycặp số vào từng bpt để kiểm tra.
Chia sẻ
Một số câu hỏi khác cùng bài thi.
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Bất đẳng thức nào sau đây đúng với mọi số thực ?
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Mệnhđềnàosauđâyđúng? Miềnnghiệmcủabấtphươngtrình lànửamặtphẳngchứađiểm
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Tính diện tích lớn nhất của hình chữnhật nội tiếp trong nửa đuờng tròn có bán kính (hình vẽ)
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Trong tất cả các hình chữ nhật có cùng diện tích ,hình chữ nhật có chu vi nhỏ nhất là:
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Cặp số là nghiệm của bất phương trình nào sau đây?
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Bất phương trình tương đương với bất phương trình nào sau đây?
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Một hộ nông dân định trồng đậu và cà trên diện tích m2. Nếu trồng đậu thì cần công và thu đồng trên m2 nếu trồng cà thì cần công và thu đồng trên m2 Hỏi cần trồng mỗi loại cây trên diện tích là bao nhiêu để thu được nhiều tiền nhất khi tổng số công không quá . Hãy chọn phương án đúng nhất trong các phương án sau
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Một xưởng cơ khí có hai công nhân là Chiến và Bình. Xưởng sản xuất loại sản phẩm và . Mỗi sản phẩm bán lãi nghìn đồng, mỗi sản phẩm bán lãi nghìn đồng. Để sản xuất được một sản phẩm thì Chiến phải làm việc trong giờ, Bình phải làm việc trong giờ. Để sản xuất được một sản phẩm thì Chiến phải làm việc trong giờ, Bình phải làm việc trong giờ. Một người không thể làm được đồng thời hai sản phẩm. Biết rằng trong một tháng Chiến không thể làm việc quá giờ và Bình không thể làm việc quá giờ. Số tiền lãi lớn nhất trong một tháng của xưởng là.
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Một gia đình cần ít nhất đơn vị protein và đơn vị lipit trong thức ăn mỗi ngày. Mỗi kiogam thịt bò chứa đơn vị protein và đơn vị lipit. Mỗi kilogam thịt lợn chứa đơn vị protein và đơn vị lipit. Biết rằng gia đình này chỉ mua nhiều nhất kg thịt bò và kg thịt lợn. Giá tiền một kg thịt bò là nghìn đồng, một kg thịt lợn là nghìn đồng. Gọi , lần lượt là số kg thịt bò và thịt lợn mà gia đình đó cần mua. Tìm , để tổng số tiền họ phải trả là ít nhất mà vẫn đảm bảo lượng protein và lipit trong thức ăn?
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Ông An muốn xây một cái bể chứa nước lớn dạng một khối hộp chữ nhật không nắp có thể tích bằng . Đáy bể là hình chữ nhật có chiều dài gấp đôi chiều rộng, giá thuê nhân công để xây bể là đồng/. Nếu ông An biết xác định các kích thước của bể hợp lí thì chi phí thuê nhân công sẽ thấp nhất. Hỏi ông An trả chi phí thấp nhất để xây dựng bể đó là bao nhiêu?
Một số câu hỏi khác có thể bạn quan tâm.
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 24 to 28:
Rural America is diverse in many ways. As we have seen, no one industry dominates the rural economy no single pattern of population decline or growth exists for all rural areas, and no statement about improvements and gaps in well-being holds true for all rural people. Many of these differences are regional in nature. That is, rural areas within a particular geographic regionof the country often tend to be similar (24) _______ each other and different from areas in another region. Someindustries, for example, are (25) _______ with different regions-logging and sawmills in the Pacific Northwest andNew England, manufacturing in the Southeast and Midwest, and farming in the Great Plains. Persistent poverty also has a regional pattern, concentrated primarily in the Southeast. Other differences follow no regional pattern. Areas that rely heavily on the services industry are located throughout rural America, as are rural areas that have little access to advanced telecommunications services. Many of these differences, regional and non-regional arethe result of a (26) _______ of factors including the availability of natural (27) ______; distance from and access tomajor metropolitan areas and the information and services found there; transportation and shipping facilities; political history and structure; and the racial, ethnic, and (28) ______ makeup of the population.
Question 25:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 15 to 19:
Fashions have always changed with time. No(15) ________ Roman girls worried about having the latest hairstyleand boys in Ancient Egypt wanted to have sandals that were cool and not the sensible ones their mothers preferred. Look(16) ________over recent times, there seem to be two main differences in the way fashions have changedcompared to earlier time. Firstly, (17) ________ morepeople have a choice of clothes available to them. Thereare few places in the world where the trainers, the caps or the T-shirts of teenagers do not change from one year to the next. Secondly, styles are (18) ________within a much shorter time than they usedto be. For instance, in the 1960s, (19) ________ had the same low waists and narrow skirts as forty years before. In the early years of the 21st century, the shops are full of long skirts and colored scarves like the ones in fashion only thirty years before. Soon, we will find that the really fashionable people look no different from the rest of us, because it is only ten years since their clothes were in fashion before!
Question 19:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 15 to 19:
Fashions have always changed with time. No(15) ________ Roman girls worried about having the latest hairstyleand boys in Ancient Egypt wanted to have sandals that were cool and not the sensible ones their mothers preferred. Look(16) ________over recent times, there seem to be two main differences in the way fashions have changedcompared to earlier time. Firstly, (17) ________ morepeople have a choice of clothes available to them. Thereare few places in the world where the trainers, the caps or the T-shirts of teenagers do not change from one year to the next. Secondly, styles are (18) ________within a much shorter time than they usedto be. For instance, in the 1960s, (19) ________ had the same low waists and narrow skirts as forty years before. In the early years of the 21st century, the shops are full of long skirts and colored scarves like the ones in fashion only thirty years before. Soon, we will find that the really fashionable people look no different from the rest of us, because it is only ten years since their clothes were in fashion before!
Question 18:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 15 to 19:
Fashions have always changed with time. No(15) ________ Roman girls worried about having the latest hairstyleand boys in Ancient Egypt wanted to have sandals that were cool and not the sensible ones their mothers preferred. Look(16) ________over recent times, there seem to be two main differences in the way fashions have changedcompared to earlier time. Firstly, (17) ________ morepeople have a choice of clothes available to them. Thereare few places in the world where the trainers, the caps or the T-shirts of teenagers do not change from one year to the next. Secondly, styles are (18) ________within a much shorter time than they usedto be. For instance, in the 1960s, (19) ________ had the same low waists and narrow skirts as forty years before. In the early years of the 21st century, the shops are full of long skirts and colored scarves like the ones in fashion only thirty years before. Soon, we will find that the really fashionable people look no different from the rest of us, because it is only ten years since their clothes were in fashion before!
Question 17:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 15 to 19:
Fashions have always changed with time. No(15) ________ Roman girls worried about having the latest hairstyleand boys in Ancient Egypt wanted to have sandals that were cool and not the sensible ones their mothers preferred. Look(16) ________over recent times, there seem to be two main differences in the way fashions have changedcompared to earlier time. Firstly, (17) ________ morepeople have a choice of clothes available to them. Thereare few places in the world where the trainers, the caps or the T-shirts of teenagers do not change from one year to the next. Secondly, styles are (18) ________within a much shorter time than they usedto be. For instance, in the 1960s, (19) ________ had the same low waists and narrow skirts as forty years before. In the early years of the 21st century, the shops are full of long skirts and colored scarves like the ones in fashion only thirty years before. Soon, we will find that the really fashionable people look no different from the rest of us, because it is only ten years since their clothes were in fashion before!
Question 16:
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phases that best fits each of the numbered blanks from 34 to 38:
People have always dreamt of living forever. Although we all know this will never happen, we will want to live as long as possible. __(34)__, there are advantages and disadvantages of a long life.In the first place, people who live longer can spend more time with their family and friends. Secondly, __(35)__ have busy working lives look forward to a long, relaxing life, when they can do the things they‘ve never had time for. __(36)__, there are some serious disadvantages. Firstly, many people become ill and consequently have to spend time in hospital or become burden __(37)__ the children and friends. Many of them find this dependence annoying or embarrassing. In addition to this, __(38)__ the fewer friends they seem to have because old friends die or become and it’s often difficult to make new friends. To sum up, living to a very old age is worthwhile for those who stay healthy enough to remain independent and enjoy life.
Question 38:
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phases that best fits each of the numbered blanks from 34 to 38:
People have always dreamt of living forever. Although we all know this will never happen, we will want to live as long as possible. __(34)__, there are advantages and disadvantages of a long life.In the first place, people who live longer can spend more time with their family and friends. Secondly, __(35)__ have busy working lives look forward to a long, relaxing life, when they can do the things they‘ve never had time for. __(36)__, there are some serious disadvantages. Firstly, many people become ill and consequently have to spend time in hospital or become burden __(37)__ the children and friends. Many of them find this dependence annoying or embarrassing. In addition to this, __(38)__ the fewer friends they seem to have because old friends die or become and it’s often difficult to make new friends. To sum up, living to a very old age is worthwhile for those who stay healthy enough to remain independent and enjoy life.
Question 37:
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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phases that best fits each of the numbered blanks from 34 to 38:
People have always dreamt of living forever. Although we all know this will never happen, we will want to live as long as possible. __(34)__, there are advantages and disadvantages of a long life.In the first place, people who live longer can spend more time with their family and friends. Secondly, __(35)__ have busy working lives look forward to a long, relaxing life, when they can do the things they‘ve never had time for. __(36)__, there are some serious disadvantages. Firstly, many people become ill and consequently have to spend time in hospital or become burden __(37)__ the children and friends. Many of them find this dependence annoying or embarrassing. In addition to this, __(38)__ the fewer friends they seem to have because old friends die or become and it’s often difficult to make new friends. To sum up, living to a very old age is worthwhile for those who stay healthy enough to remain independent and enjoy life.
Question 36:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 31 to 35:
In the western customs (31) _____ hands is the customary form of greeting, but in China a nod of the head or (32) ____ bow is sufficient. Hugging and kissing when greeting are uncommon. Business cards are often (33) _____ and yours should be printed in your own language and in Chinese. Also, it is more respectful to present your card or a gift or-any other article using (34) _____ hands. The Chinese are (35) _____ applauders. You may be greeted with group clapping, even by small children. When a person is applauded is this practice it is the custom for that person to return the applause or a “thank you”.
Question 35:
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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word or phrase thet best fits each of the numbered blanks from 31 to 35:
In the western customs (31) _____ hands is the customary form of greeting, but in China a nod of the head or (32) ____ bow is sufficient. Hugging and kissing when greeting are uncommon. Business cards are often (33) _____ and yours should be printed in your own language and in Chinese. Also, it is more respectful to present your card or a gift or-any other article using (34) _____ hands. The Chinese are (35) _____ applauders. You may be greeted with group clapping, even by small children. When a person is applauded is this practice it is the custom for that person to return the applause or a “thank you”.
Question 33:
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