Cho \(\frac{x}{a}=\frac{y}{b}\) . Chứng minh rằng \(\left(x^2+y^2\right)\left(a^2+b^2\right)=\left(ax+by\right)^2\)

Cho tam giác ABC. Gọi I là giao điem của ba đường phân giác của tam giác. Từ I hại IH vuông góc với BC tại H. Biết BC = a, CA = b, AB = c và IH = r .

a) Tính diện tích tam giác IBC theo a và r

b) Gọi S là diện tích của tam giác ABC. Chứng minh rằng S =\(\frac{a+b+c}{2}.r\)

Chứng tỏ rằng H(x) = x(6 - x) không có nghiệm

II.Circle a mistake in A,B,C or Dand correct it

1.Critics found his performance as King Lear disappointed

A .found B. performance C.as D.disappointed

2.Titanic film made a strong impression for me

A.made B.a C.impression D.for

3.Daniel Craig and Halle Berry are both entertaining and talent actors

A .are B.entertaining C.talent D.actors

4.My uncle drove careless some years ago , but now he doesn't

A.drove B.careless C.but D.doesn't

I.Circle the best answer ( A , B , C or D ) to complete the sentences

1.We will go on holiday with some friends of ...

A.our B. ours C.us D.we

2.The city will have to find a solution to reduce traffic jam , .... ?

A.does it B. won't it C.will it D.doesn't it

3.Vanilla sky ... Tom Cruise , Peslelope Cruz and Cameron Diaz

A.acts B.plays C.stars D.does

4.I'm tired of ... nothing to do at home

A.to have B.have C.having D.had

5.I am sure I locked the door . I clearly remember ... it

A.to lock B. to have lock C locking D.lock

IV.Sửa lỗi sai

1.We first met when he became the manager of the bank

2.I sometimes call on my younger sister when i'm in london

3.After we had eaten , we played cards

4.Take a pack lunch with you , in case you get hungry

5.There was a power failure earlier today and the trains are all running late now

6.He behaved in such a silly way I was ashamed of him

7.We served drinks as soon as our friends arrived

8.Dad found his change between the couch cushions

9.To tracks my running speed , I use a stopwatch

10.Carter put wood in the fireplace to keep the cabin warm

11.Christina went to the grocery store

12.The carpenter hit the nail with a hammer

III.Choose the correct option A,B,C or D to complete the sentences

1.They cancelled the flight to France ... fog

A.because B.despite C.because of D. although

2.In the future , most people will travel ... flying trains

A.in B.at C.on D.with

3.Drivers have to ... your seatbelt whenever they drive

A.tie B.fasten C.put on D.put

4.We were ... with the lastest film of that director

A.satisfied B.satisfactory C.satisfying D.satisfy

5.La Tomatina is a ... festival to celebrate the tomato harvest

A.year B.seasonal C.season D.annually

6.People put pumpkin ...outside the homes during Halloween

A.lights B.lanterns C.neon signs D.neon signs

7.A lot of cultural and ... activities are held as part of the Flower Festival in Da Lat

A.art B.artist C. artistic D.arts

8.People of ... minorities in Phu Yen celebrate Hoi Mua Festival every March

A.ethnic B.local C.native D.village