\(\left\{{}\begin{matrix}x+2+\dfrac{2}{\sqrt{y}-3}=9\\2x+4-\dfrac{1}{\sqrt{y}-3}=8\end{matrix}\right.\)

Tìm ĐKXĐ của hệ phương trình

A= \(\dfrac{3}{\sqrt{7}-2}\)+ \(\sqrt{\left(\sqrt{7}-3\right)^2}\)
B= \(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{\sqrt{x}}{x-\sqrt{x}}\right):\dfrac{\sqrt{x}+1}{x-1}\)
a) Rút gọn A, B
b) Tìm các giá trị của x để B<A

Rewrite

I was pleasantly surprised at the result of the meeting (came)

 

A= \(\dfrac{3}{\sqrt{7}-2}\) + \(\sqrt{\left(\sqrt{7}-3\right)}^2\)
B= \(\left(\dfrac{\sqrt{x}}{\sqrt{x}-1}-\dfrac{\sqrt{x}}{x-\sqrt{x}}\right)\):\(\left(\dfrac{\sqrt{x}+1}{x-1}\right)\)
Rút gọn A,B

Read the passage below and choose one correct answer for each question. ( 1)
Robert Edwards was blinded in an automobile nine years ago. He was also partially deaf because of age. Last week, he was controlling near his home when a thunderstorm approached. He took refuge under a tree and was struck by lightning. He was knocked to the ground and woke up some 20 minutes later, lying face down in water below a tree. He went into the house and lay down in bed. A short time later, he awoke; his legs were numbed and he was trembling, but, when he opened his eyes, he could see the clock across the room fading in and out in front of him. When his wife entered, he saw her for the first time in nine years. Doctor confirmed that he has regained his sight and hearing apparently from the flash of lightning, but they were unable to explain the occurrence. The only possible explanation offered by one doctor was that, since Edwards lost his sight as a result of trauma in a terrible accident, perhaps the only way it could be restored was by another trauma.
1. What caused Robert Edwards’s blindness?
A. He was struck by lightning.                                        B. He was very old.
C. He was in a car accident.                                            D. He fell down in his yard.
2. What was the first thing that he saw after being struck by lightning?
A. his wife                           B. a clock                 C. a tree                  D. lightning
3. Which of the following statements is Not true?
A. Edwards had been blind for nine years.
B. Edwards was unconscious for twenty minutes after the lightning had struck him.
C. Doctor believes that Edwards was never really blind or deaf
D. Edwards awoke with his face in a puddle of water.
4. What was Edwards doing when he was struck by lightning?
A. hiding from the storm under a tree
B. climbing a tree
C. driving a car
D. lying on the ground
5. What was the reason given by one doctor that Edwards regained his sight?
A. He gained his sight from a head injury when he fell from a tree.
B. He was happy after his wife entered his room for the first time in nine years.
C. The lightning took the feeling from his legs and gave feeling in his eyes.
D. Because the blow that blinded him was very severe, it took another very severe blow to restore his sight.