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Năm ngoái mk thi thì là đề viết về "My dream house"!Còn năm nay thì mk ko biết!!
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Ta có 3x( y + 1 ) + y + 1 = 7
3x( y + 1 ) + ( y + 1 ) = 7
( 3x + 1 )( y + 1 ) = 7
Vì x; y nguyên nên 3x + 1 và y + 1 nguyên
Vậy ( 3x + 1 ); ( y + 1 ) ϵ Ư( 7 ) = { 1; -1; 7; -7 }
Lập bảng giá trị
3x + 1 | 1 | -1 | -7 | 7 |
y + 1 | 7 | -7 | -1 | 1 |
x | 0 | \(\dfrac{-2}{3}\) ( loại ) | \(\dfrac{-8}{3}\) | 2 |
y | 6 | 0 |
Vậy các cặp số nguyên ( x; y ) cần tìm để 3x( y + 1 ) + y + 1 = 7 là ( 0; 6 ); ( 2; 0 )
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\(2xy-6y=10-x\)
\(2xy-6y-10+x=0\)
\(\left(2xy-6y\right)+\left(x-3\right)-7=0\)
\(2y\left(x-3\right)+\left(x-3\right)=7\)
\(\left(x-3\right)\left(2y+1\right)=7\)
Vì x, y là số nguyên nên x-3;2y+1 là số nguyên
Mà (x-3)(2y+1)=7 => x-3 ; 2y+1 thuộc Ư(7)
Mặt khác Ư(7) = { 1;-1;7;-7}
Ta có bảng sau:
x-3 | 1 | -1 | 7 | -7 |
2y+1 | 7 | -7 | 1 | -1 |
x | 4 | 2 | 10 | -4 |
y | 3 | -4 | 0 | -1 |
Vậy cặp (x;y) nguyên thỏa mãn là (4;3) ; (2;-4) ; (10;0) ; (-4;-1)
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1 . Students to live in the big city in Vietnam.
2 . My uncle took me to see the one pillar pagoda last sunday
3 . Nga did not go to school because she was tired
4 . Hanh needs to buy some stamps mail for overseas.
cho em nha. câu cuối nếu sai thì chị sửa cho em nha.
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Choose the letter A, B, C or D the word that has the underlined part different from others :
A. scissors (ə)
-> B. brother (ʌ)
C .computer (ə)
D. calculator (ə)
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Bạn vào link này nhé!
https://www.anhngumshoa.com/tin-tuc/tat-tan-tat-ve-12-thi-trong-tieng-anh-co-ban-ndash-cong-thuc-cach-dung-va-dau-hieu-nhan-biet-37199.html
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My name is Nhung. Today I'm going to tell about my best friend. I have many friends. But among my friends, I cherish most is Lan. She is a good student of my class. Lan has short black hair, an oval face and brown eyes. I when she glad because she looks so lovely when she smiles. She is a form of friends that I can share everything. She always help me in every situations. She s English, reading books and listening to music. Lan and I have a lot of common with each other, so we have been good friends over past years. I hope we will keep this friendship forever.
hi im Phuong. I have a lot of friends. my cherish most is Anh. she a good and clever friend. she has long black hair and brown eyes. she high 1m45. she so clever. sometime she greedy and kind.she favorite lesson is music. she play skipping . in the future she want to a doctoc
Đây mà là Tiếng Anh ak ?
Đây là toán chứ bạn