Tìm điều kiện để biểu thức sau c nghĩa

B = \(\sqrt{\frac{-3}{x-1}+}\sqrt{x^2+4}\)

Trục căn

\(\frac{1}{\sqrt[3]{3}+\sqrt[3]{2}}\)

Tìm x

\(\left(\sqrt{x}+\frac{1}{\sqrt{x}+1}\right).\left(1-\frac{\sqrt{x}+2}{x+\sqrt{x}+1}\right)\)>0

So sánh

\(\sqrt{4+\sqrt{7}-}\sqrt{4-\sqrt{7}}va\sqrt{3}\)

Pisa is _ _ m _ _ _ for its leaning tower.

22) The crew and the passengers were evacuated after a phone-call from an unknown man who said there was a bomb on _ _ a _ _ of the plane.

23) It’s a meteorologists’s job to _ _ _ e _ _ _ _ the weather to come.

24) This oak table was the first piece of _ _ r _ _ t _ _ _ that we bought after moving into our new house.

25) Don’t forget to fasten the _ _ a _ b _ _ _ before you start driving.

26) I was born on 22 August 1999 and what is your date of _ _ r _ _ ?

27) The Prime Minister is the head of the _ _ v _ _ _ m _ _ _ .

28) We’ve taken a long-term loan from the bank. We’ve been in _ _ b _ ever since.

29) Mr. Pearlman will certainly know what to do. He’s been working as a tax advisor for twenty five years now. He has a great _ x _ _ _ i _ _ c _ .

30) Coca-cola was _ _ v _ _ _ _ d by Dr John Pemberton whose receipt has always been kept secret.

31) Hello, Mike. It’s nice to see you. Come in and __________ yourself at home.

A. feel ​​​B. make​​​C. find​​​D. treat

32) It hasn’t been reported yet what __________ the underground explosion in the coal mine.

A. caused​​B. resulted​​C. led​​​D. performed

33) I can lend you a pencil. I have a _________ one.

A. unoccupied​​B. loose​​​C. spare​​​D. more

34) We know the Browns very well. They’ve lived __________ to us for ages.

A. opposite​​B. apart​​​C. next​​​D. beside

35) A few of the older boys were __________ of bullying the younger pupils.

A. sentenced​​B. accused​​C. charged​​D. blamed

36) You’re always making up stories. Stop making a __________ of me.

A. fool ​​​B. stupid​​C. silly​​​D. crazy

37) Barbara and Sam __________ in love with each other the moment they met.

A. got​​​B. stood​​​C. drove ​​D. fell

38) It looks like the engine has __________ down but I won’t help you. I can’t repair car engines.

A. broken​​B. fallen​​C. set ​​​D. turned

39) I said Jim but I meant Tim. It was just a __________ of the tongue.

A. slide​​​B. slap​​​C. slick​​​D. slip

40) I quite like Ronald but I can’t __________ his nasty habit of spitting in the street.

A. stay​​​B. exist​​​C. stand​​​D. allow

Cho đoạn thẳng ab, c thuộc đoạn thẳng ấy sao cho AC = \(\frac{1}{3}\)AB. Vẽ về 2 phía AB các tia Ax, By vuông góc AB. Trên Ax lấy điểm D, trên By lấy điểm E sao cho CE =2CD. Chứng minh D, C, E thẳng hàng

Cho hình chữ nhật ABCD. Gọi H là chân đường vuông góc kẻ từ A đến BD. Lấy điểm E trên DH và điểm K trên BC sao cho DE/DH = CK/CB.

Chứng minh rằng a, tam giác ade ~ tam giác ack

b, tam giác aek ~ tam giác adc

Chứng tỏ \(^{ }a^2+\frac{1}{4}>=a\)