tìm parabol (P) y= ax^2+bx+c, biết rằng P đi qua 3 điểm A (1;-1), B(2;3), C(-1;-3)

xác định parabol y= a^2+bx+2 biết rằng p đi qua điểm m (1;5) và có trục đối xứng là đường thẳng x= -1/4

cho phương trình x^2-(m+3)x+2m+2=0 với m là tham số. Tìm giá trị của tham số m để 

a. phương trình có nghiệm x=3 

b. phương trình có 2 nghiệm phân biệt x1x2 sao cho x1^2+x2^2=13

read the text then answer the question that follow

Energy is very important in modern life. People use energy to run machines, heat and cool their homes, cook, give light, transport people and products from place to place. Most energy nowadays comes from fossil fuels such as petroleum, coal and natural gas. However, many people are worried about them because burning fossil fuels causes pollution. In addition, if we don’t find new kinds of energy, we will use up all the fossil fuels in the 21st century. Scientists are working to find other energy sources for the future

1. are petroleum, coal, and natural gas fossil fuels?

2. what will happen if we don't find new kinds of energy?

PART 1. Give the right tense and form of the verbs in brackets (1.5m) GIẢI THÍCH HỘ EM NHÉ, EM CẢM ƠN Ạ, CHÚC MỌI NG MỌI ĐIỀU NHA! 1. This teacher usually (read)........ newspapers when she has free time. 2. My mother (teach) ... my sister how to cook some favorite dishes now. 3. Maryam (know)....... Lan for over two years. 4. Traditionally, the "ao dai" (wear).....by both men and woman 5. Would you like (have).....something to eat? 6. We are all looking forward to (hear)... .. from you. PART 2. Give the right form of the words in brackets to finish the following sentences (1m) 1. She was really ........by the beauty of the city. (impress) 2. The Kien Thuc Ngay Nay is .....read by both teenagers and adults. (wide) 3. The journey to the village is very .... (interest) 4. To keep the air unpolluted, people ought to use .......energy to create electricity. (sun)

Part 3: Give the correct form of the verb in brackets. (1,5 m)  HUHU GIẢI THÍCH GIÚP T VỚI Ạ, T CẢM ƠN RẤT NHIỀU, NHANH GIÚP T NHÉ TẠI T CẦN GẤP RẤT GẤP Ạ

Famous places in Ha Noi (visit) ………………every year.

Lan (move) ………………………….to Ho Chi Minh city with her family last summer.

Those students (walk) ………………..up the mountain to visit the shrine of a Vietnamese hero at present.

If we use much pesticide on vegetables, the vegetables (become)……………….poisonous and inedible.

How about (make)…………………….posters on energy and hanging them around our school?

Would you like (have)………………..a drink?

Part 4: Give the correct forms of the words in the brackets to finish the following sentences. (1,0 m)

What have fashion designers done to (modern)…………………the ao dai?

A computer can gather a lot of (inform)……………………for different purposes.

In order to keep our environment (pollute) ……………….., we shouldn’t drop litter in public places.

Our teacher is pleased that we solved the problems (effect) ……………………..

Part 5: Choose the words or phrases in brackets that best completes each sentence. (1,0 m)

Jeans have never been out of fashion, and today young generation is still fond (in/ on/ at/ of) ………….wearing them.

(A/ An/ The/ Every)…………….Parkers are nice, so van feels like a member of their family.

You (did/ didn’t do/ had/ hadn’t)……………your homework last night, did you?

If we (go on/ turn off/ look after/ take away)……………throwing garbage, the environment will be contamined.

Part 4: Give the correct form of the word in brackets. (1 m) GIẢI THÍCH GIÚP EM NHÉ! CẢM ƠN RẤT NHIỀU Ạ!

1. This stamp (collect)………………………......is valuable.

2. The villagers welcomed the visitors (warm).)...........................................

3. In some areas, water has to be boiled to (pure)....................................it.

4. Don't worry about the volcano. It's been (act)....................................for years.        Part 7: Combine each pair of the following sentences into one, using the word in brackets. (1,5 m)

1.Namhas just bought a laptop. It is very expensive.          (WHICH)

2. My mother was tired. She helped me with my homework.      (ALTHOUGH)

3. My sister studied every subject hard. She won her school's Best Student Prize last year         (THEREFORE)

Part 8: Finish each sentence in such a way that it means exactly the same as the one printed before it. (1,5m)

1. Lan said to me, "I am waiting for my parents now."

-> Lan told me......................................................................................

2. We can't have a holiday because we don't have enough money.

-> If we............................................................................................

3. Mr. John is going to take all the students to the beach.

->All the students..............................................................................

Part 2: Choose the word or phrase in brackets that best completes each sentence. (1,5 m)/ GIẢI THÍCH CHO MÌNH LUÔN NHÉ, KHÔNG GIẢI THÍCH THÌ KH CẦN TRẢ LỜI ĐÂU NHA!

1. You seem to be quite good (for/about/at/to)..................................physics.

2. - A: "I suggest fixing the dripping faucet." - B: “(We will/ Good idea! / Yes, please/ You are welcome).........."

3. - A: How (far/long/ often/ much).................do you play football? - B: Twice a week.

4. He always takes full (advantage/ benefit/profit/ advice).................of the mistakes made by the competitors.

5. Mount Pinatubo, which is a volcano in (a/an/the/some)................Philippines, erupted in 1991.

6. Students in secondary schools should wear uniforms, (shouldn't they/ should they/ should he/ shouldn't he) ..............?

Part 3: Give the correct form of the verb in brackets. (1,5 m)

1. Our friends suggest (go)………………...... on a picnic next week.

2. Please don't make so much noise. I (check)..........................my assignment before handing it in.

3. Our dustbins (empty) …………………….. every Monday.

4. Just as I (wonder).......................................what to do next, the phone rang.

5. Maryam wishes she (have) ………………..a trip toVietnam again next year.

6. Congratulations, Trang. You (just, win)................................the first prize in the English Speaking Contest.