Giải hệ phương trình :

\(\left\{{}\begin{matrix}x^3+7y=\left(x+y\right)^2+x^2y+7x+4\\3x^2+y^2-8y+4=8x\end{matrix}\right.\)

Vẽ đường thẳng a. Trên đường thẳng a vẽ đoạn AB = 6 cm. Vẽ tiếp đường thẳng d đi qua điểm A và vuông góc với a. Vẽ đường thẳng d' đi qua điểm B và vuông góc với a. Hai đương thẳng d và d' có cắt nhau không?

Viết các phân số sau đây dưới dạng số thập phân vô hạn tuần hoàn:  − 1 3 ; 4 7 ; 2 24 33 ; − 1 19 132 ; 4 9 ; 13 45 .

Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

Quite different from storm surges are the giant sea waves called tsunamis, which derive their name from the Japanese expression for “high water in a harbor.” These waves are also referred to by the general public as tidal waves, although they have relatively little to do with tides. Scientists often referred to them as seismic sea waves, far more appropriate in that they do result from undersea seismic activity.

Tsunamis are caused when the sea bottom suddenly moves, during an underwater earthquake or volcano for example, and the water above the moving earth is suddenly displaced. This sudden shift of water sets off a series of waves. These waves can travel great distances at speeds close to 700 kilometers per hour. In the open ocean, tsunamis have little noticeable amplitude, often no more than one or two meters. It is when they hit the shallow waters near the coast that they increase in height, possibly up to 40 meters.

Tsunamis often occur in the Pacific because the Pacific is an area of heavy seismic activity. Two areas of the Pacific well accustomed to the threat of tsunamis are Japan and Hawaii. Because the seismic activity that causes tsunamis in Japan often occurs on the ocean bottom quite close to the islands, the tsunamis that hit Japan often come with little warning and can, therefore, prove disastrous. Most of the tsunamis that hit the Hawaiian Islands, however, originate thousands of miles away near the coast of Alaska, so these tsunamis have a much greater distance to travel and the inhabitants of Hawaii generally have time for warning of their imminent arrival.

Tsunamis are certainly not limited to Japan and Hawaii. In 1755, Europe experienced a calamitous tsunami, when movement along the fault lines near the Azores caused a massive tsunami to sweep onto the Portuguese coast and flood the heavily populated area around Lisbon. The greatest tsunami on record occurred on the other side of the world in 1883 when the Krakatoa volcano underwent a massive explosion, sending waves more than 30 meters high onto nearby Indonesian islands; the tsunami from this volcano actually traveled around the world and was witnessed as far away as the English Channel.

The passage suggests that the tsunamis resulting from the Krakatoa volcano _____.

A. resulted in little damage

B. caused volcanic explosions in the English Channel

C. actually traveled around the world

D. was unobserved outside of the Indonesian islands

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

His physical conditions were no impediment to his career as a violinist.

A. help

B. impotence

C. hindrance

D. impossibility

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 28 to 34.

  Southern Thailand was hit Thursday by the most severe haze from forest fires in Indonesia, forcing all schools in a province to close and disrupting flights in a popular tourist area, officially said.

  The haze that has shrouded parts of Malaysia and Singapore for nearly two months reached hazardous levels in the southern Thai city of Songkhla, with the pollution index hitting a record-high reading of 365. A reading of 101-200 is unhealthy, 201-300 is very unhealthy and above 300 is hazardous.

  “This is a crisis,” said Halem Jemarican, head of the Southern Environment Office. He said the pollution index in southern Thailand has never exceeded 300 before. Halem said his office has worked with other authorities to have all schools in Songkhla province send students home and all outdoor sports stadiums to close temporarily. Warnings have been issued to vulnerable people such as children, the elderly and people with illnesses not to go out of their homes.

  “The wind speed is very low this year in the south, causing haze to stay in our skies longer,” Halem said by telephone.

  An airport official in Hat Yai, a popular tourist area, said three flights bound for Bangkok were delayed Thursday morning because of the haze. A flight from Bangkok to Hat Yai was diverted to Surat Thani on Wednesday evening. The official declined to be identified because of working rules.

  Local media reported that cloud seeding has been discussed as a way to dispel the haze in southern Thailand, which is hundreds of kilometers (miles) from the forest fires in Indonesia’s Sumatra island.

  Southern Thailand boasts tropical beaches popular among tourists in Surat Thani and Phuket, two of the seven provinces suffering from the haze.

What is the main idea of paragraph 2?

A. Thailand is the most polluted country in Asia

B. Thailand’s pollution index reads 201-300

C. The haze reached a dangerous level

D. People living in Songkhla do a lot of reading

Có bao nhiêu số phức z thỏa mãn: z - i = 2  và z 2  là số thuần ảo:

A. 3

B. 1

C. 4

D. 2

Trên mặt phẳng tọa độ Oxy, tập bởi biểu diễn số phức z thỏa mãn − 2 + i z − 1 = 5 . Phát biểu nào sau đây sai ?

A. Tập hợp điểm biểu diễn số phức z là đường tròn tâm I 1 ; − 2 .

B. Tập hợp điểm biểu diễn số phức z là đường tròn bán kính R=5

C. Tập hợp điểm biểu diễn số phức z là đường tròn có đường kính là 10.

D. Tập hợp điểm biểu diễn số phức z là hình tròn bán kính R=5