Đáp án + Giải thích các bước giải:
`(x)/(y)=(12)/(17)`
`->(x)/(12)=(y)/(17)`
Đặt `(x)/(12)=(y)/(17)=k`
`->` $\begin{cases} x=12k \\ y=17k \end{cases}$
Ta có :
`x.y=816`
`->12k.17k=816`
`->204k^{2}=816`
`->k^{2}=4`
`->k=+-2`
`+)` Với `k=2`, ta được :
$\begin{cases} x=12.2=24 \\ y=17.2=34 \end{cases}$
`+)` Với `k=-2`, ta được :
$\begin{cases} x=12.(-2)=-24 \\ y=17.(-2)=-34 \end{cases}$
Vậy `(x;y)=(24;34);(-24;-34)`
Đáp án+Giải thích các bước giải:
$\\$`x/y=12/17=>x/12=y/17`$\\$`Đặt,x/12=y/17=k`$\\$`=>x=12k;y=17k`$\\$`+)Do,xy=816=>12k.17k=816=>k^2. 204=816`$\\$`=>k^2=4=>k=+-2`$\\$`TH1 :k=2`$\\$`=>{(x=12.2=24),(y=17.2=34):}`$\\$`TH2 :k=-2`$\\$`=>{(x=12.(-2)=-24),(y=17.(-2)=-34):}`
Câu 1:Vườn trường có trồng cây ăn quả trong đó số cam chiếm tổng số cây, số bưởi chiếm tổng số cây, còn lại là 6 cây xoài. Hỏi vườn trường có bao nhiêu cây ? Câu 2 :Trong một nhà máy, cuối năm số công nhân được thưởng nếu thêm 2 người thì được số công nhân, số công nhân không được thưởng nếu giảm 14 người thì bằng tổng số công nhân. Hỏi nhà máy có bao nhiêu công nhân được thưởng ? gấp nhaa
a chị nào chuyên anh giúp e với ạ e cảm ơn Write a summary of the Perfect swan not more than 100 words The perfect swan There was once a Chinese emperor named Zhang Wei. He was a strong and powerful man, but he was also kind and took care of his people. However, there was one problem - he had a bad temper and became angry very quickly. Zhang Wei loved art. He owned thousands of paintings, but he always wanted one more. One day he asked his assistant, Hong, 'Who is the most famous painter in China?' 'His name is Cheng Li,' replied Hong. 'He's the best artist in the country.' 'Excellent!' said Zhang Wei. 'Do you think he could paint a beautiful swan for me?' 'If you ask him, he'll paint any animal you like,' replied Hong. Zhang Wei invited the artist, Cheng Li, to his palace. 'Cheng Li!' said Zhang Wei. 'Will you paint a picture of a swan for me?' 'Of course,' replied Cheng Li. 'But it will take some time.' 'I understand,' said Zhong Wei, 'You can stay at the palace until you've finished the painting.' After one year, Zhang Wei visited Cheng Li in his room at the palace. 'Cheng Li!' said Zhang Wei. 'Is my painting ready yet?' I'm sorry,' said Cheng Li. 'Swans are not easy to paint. I'm going to need more time. Could you please come back in another year?' One year later, the emperor returned, but the painting still wasn't ready. Zhang Wei was furious. 'I'll give you one more year!' he shouted. 'If my painting isn't finished, you'll be sorry!" Another year later, Zhang Wei came back to collect the painting. Cheng Li put a large sheet of paper on the table. Then he took a brush and some ink and painted the most beautiful swan the emperor had ever seen. Zhang Wei was astonished. That... is... perfect!' he cried. 'It's magnificent!" But Zhang Wei was still furious. I've waited for three years,' he shouted, and you painted this swan in two minutes! How dare you make a fool of me!' He was so angry that he sent Cheng Li to a land far away and told him never to return to China. A week later, Zhang Wei told his servants to empty Cheng Li's room in the palace. Zhang Wei was astonished when his servants found thousands of paintings of swans. The emperor suddenly realised his mistake. Cheng Li wasn't slow or lazy. He had practised every day for three years until he learnt how to paint the perfect swan. Zhang Wei had made a terrible mistake because of his bad temper. He sent a message to Cheng Li to say sorry and invited him to come back to China. Cheng Li forgave Zhang Wei and returned to live in the palace as the emperor's royal painter.
giúp tui câu 20************************************
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giúp mình với mình cần gấp huheo :(((
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Con lắc lò xo treo thẳng đứng có k= 40N/m và m = 100g dao động tại nơi có g = 10m/s2. Khi vật dao động thì chiều dài của lò xo lúc ngắn nhất vừa bằng với chiều dài tự nhiên của lò xo. Biên độ dao động của con lắc là:
9. Oil spills, garbage and dirty air are examples of __________. A. ocean B.tanker C.pollution D.sea 10. A ____________is a big ship which transports oil across the ocean. A.boat B.subway C.garbage D.tanker 11.When tankers have accidents and oil escapes, the result is_________. A.a fire B.an oil spill C.a drought D. a flood 12. You must ________ to bed early. A to go B. went C. go D.going 13. We _________ throw trash into the oceans. A. mustn't B. can C. have to D. haven't to
Write a summary of the Perfect swan not more than 100 words The perfect swan There was once a Chinese emperor named Zhang Wei. He was a strong and powerful man, but he was also kind and took care of his people. However, there was one problem - he had a bad temper and became angry very quickly. Zhang Wei loved art. He owned thousands of paintings, but he always wanted one more. One day he asked his assistant, Hong, 'Who is the most famous painter in China?' 'His name is Cheng Li,' replied Hong. 'He's the best artist in the country.' 'Excellent!' said Zhang Wei. 'Do you think he could paint a beautiful swan for me?' 'If you ask him, he'll paint any animal you like,' replied Hong. Zhang Wei invited the artist, Cheng Li, to his palace. 'Cheng Li!' said Zhang Wei. 'Will you paint a picture of a swan for me?' 'Of course,' replied Cheng Li. 'But it will take some time.' 'I understand,' said Zhong Wei, 'You can stay at the palace until you've finished the painting.' After one year, Zhang Wei visited Cheng Li in his room at the palace. 'Cheng Li!' said Zhang Wei. 'Is my painting ready yet?' I'm sorry,' said Cheng Li. 'Swans are not easy to paint. I'm going to need more time. Could you please come back in another year?' One year later, the emperor returned, but the painting still wasn't ready. Zhang Wei was furious. 'I'll give you one more year!' he shouted. 'If my painting isn't finished, you'll be sorry!" Another year later, Zhang Wei came back to collect the painting. Cheng Li put a large sheet of paper on the table. Then he took a brush and some ink and painted the most beautiful swan the emperor had ever seen. Zhang Wei was astonished. That... is... perfect!' he cried. 'It's magnificent!" But Zhang Wei was still furious. I've waited for three years,' he shouted, and you painted this swan in two minutes! How dare you make a fool of me!' He was so angry that he sent Cheng Li to a land far away and told him never to return to China. A week later, Zhang Wei told his servants to empty Cheng Li's room in the palace. Zhang Wei was astonished when his servants found thousands of paintings of swans. The emperor suddenly realised his mistake. Cheng Li wasn't slow or lazy. He had practised every day for three years until he learnt how to paint the perfect swan. Zhang Wei had made a terrible mistake because of his bad temper. He sent a message to Cheng Li to say sorry and invited him to come back to China. Cheng Li forgave Zhang Wei and returned to live in the palace as the emperor's royal painter.
Calli : " Em bé thông minh " Tradi / digi đều đc :) Tone hồng pastel or đen
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