chứng minh rằng

x²+5x+3\(\ge\)\(-\frac{1}{4}\)

Đọc đoạn văn sau và trả lời câu hỏi

My husband and i had a problem about our holiday last year. I wanted to have a lazy seaside holiday because i was tired and needded to relax. I loved lying in the sun, drinking iced beer and read a good book. But Robert liked busy, cultural holidays.He liked visiting museums and art galleries. He hated sunbathing because he always went red not brown. The travel agent tried to help as and suggested greece. I said i love to sail to a quiet island, bot of course, Robert said he would like to stay in atherns.It was easy to decide west to do we flew to artherns to gether, Robert stayed there and i traveled to the island of kos!

Questions

a/ Where did they go for the holiday last year?

b/ What did the wife like doing?

c/Did the husband travel to the island of kos ?

d/ Why did the wife want to have a lazy seaside holiday?

điền vào chỗ trống với các từ đã cho sẵn

celebrate ; time ; tree ; cards ; turkey ; presents

Hi! I'm Dean. I'm from England, my favorite (1) ... of the year is christmas, which is on 25 December. That's when christians (2) .... the birth of christ. In the middle of December. We send a lot of (3) ... to our friends and family, here and abroad.Then we get a big (4) .... and decorated it with lights and other things. On christmas day, we give each other (5) .... .We have one enormous meal with (6) ...., and after that, we have a christmas pudding.

chuyển đổi những câu sau

a/ Mary asked me :"Do you to visit Con Dao?"

Mary asked me

b/ I asked Nam, "Are you free tonight?"

I asked Nam

c/ "I'm decorating my christmas tree" Hoa said

Hoa said that

d/ May I borrow your pen?

Would you mind

Thay đổi những câu chủ động này thành câu bị động

a/A robber broke the window of the shop

b/Nasa will look after my little brother

c/They have cleaned the car

chọn câu đúng

1/ jack .... his homework between 8pm and 9pm yeaterday

A. did B.was doing C.made D.was making

2/ The .... festival is a festival in which people have their bulls fight againist each other

A. whale watching B.mountain-climbing C.bull-fighting D.rice-cooking

3/ The volcano was pouring out the .... when we flew overhead

A.lava B.fish C.souvenir D.water

4/ "the windy city" is another name of

A.New york B.Viet Nam C.England D.Chicago

5/ While Hoa was eating, the phone ....

A.ring B.rang C.to ring D.was ring is

6/ The christmas cards as to send christians ..... to friends

A.thanks B.tree C.greetings D.songs

7/ Eiffel tower is the tallest structure in paries of ...

A.France B.England C.Australia D.China

8/ .... is an area of land between hills on mout airs

A.valley B.Beach C.Bay D.island

9/ It was a hot and .... during sundy afternoon

A. wet B.humid C.rainy D.snowy

10/ Children should .... to respect their elders

A.be teach B.be taught C.be teaching D.be teached

chọn từ có phát âm khác với các từ còn lại

1) A.river B.pottery C.plumber D.fetch

2) A.council B.about C.without D.throughout

Tìm khối lượng NaCl và nước có trong 500g dung dịch biết rằng độ tan của chất đó ở 25 độ c là 36 g

cho tam giác ABC nhọn, H là trực tâm của tam giác ABC

chứng minh rằng : \(\frac{BH.CH}{AB.AC}+\frac{CH.AH}{BC.AB}+\frac{AH.BH}{AC.BC}=1\)

cho tam giác ABC vuông tại A, M\(\in\)AB,kẻ BD vuông góc với CM,CD thuộc đường thẳng CM). Đường thẳng BD cắt AC kéo dài tại E.chứng minh rằng

a/ AE.EC=ED.EB

b/ BD.BE + CA.CE=BC²