@lê.t.hà

$1.$ Cho 5 điểm A, B, C, D, E phân biệt. Có bao nhiêu vectơ khác vectơ-không, có điểm đầu và điểm cuối là các điểm đã cho. $2.$ Cho tam giác đều ABC cạnh bằng a. Tính độ dài của các vectơ \overrightarrow{AB}+\overrightarrow{BC} và \overrightarrow{AB}-\overrightarrow{AC} $3.$ Cho \vec{a},\vec{b}...

1. Giải hệ phương trình: \left\{\begin{matrix} x^{3}-y=x^{2}y-x & & \\ x^{3}+6y^{2}+16x-1=(7-x)\sqrt{3-x} & & \end{matrix}\right. 2. Cho a, b, c là các số thực dương thỏa mãn a+b+c=1 Tìm max: P=\sqrt{a^{2}+abc}+\sqrt{b^{2}+abc}+\sqrt{c^{2}+abc}+9\sqrt{abc}

Hi Sue, it's me, Tina. Listen, I know we had plans to watch a movie together at your house, but I don't think I can come. I don't feel too well. I finally finished working on my project, but now I have a headache. I think I will have some chicken soup and then go to bed early. It's nothing...

This is Petra Harris with a programme announcement. On Wednesday evening we have a special programme from Africa. Brian Williams is a reporter and he lived there with a group of elephants for six months. This is his story. There are some sad moments, for example when Gemma, a baby elephant dies...

MAN: What do you want to buy Mom for a birthday present? WOMAN: I do not know. Let's go to the store. Maybe we will get some ideas. MAN: Okay, great. Do you want to go tonight? WOMAN: Sorry, I cannot tonight. Can you go another time? MAN: We will have to do it soon. Her birthday party is next...

MAN: Have you been to this restaurant before? WOMAN: Yes, a few times actually. I find the waiters here are really very good – they always check you’ve got everything you need… MAN: And the manager seems very friendly too. WOMAN: He is… Anyway .. have you had a look at the menu? MAN: Yes, the...

WOMAN: So how long have you lived here? MAN: I've lived in this house for about two years. WOMAN: This is a very big house. Do you live alone or with family or friends? MAN: My brother is living with me for now. WOMAN: Oh, it must be nice to live with your brother. MAN: Yes. Actually, our sister...

WOMAN: Do you ever go swimming, Pete? MAN: Not much these days. I really miss it. WOMAN: Oh, you should start again. It's good exercise, and it's not too expensive. MAN: Yes, you're right. One time last month I went swimming with my son. WOMAN: Oh, is there a pool close to your house? MAN...

WOMAN: I'm thinking of selling the car. MAN: Well, it is quite old I suppose. WOMAN: No, it's not that, it's in very good condition ... MAN: Are you looking for something bigger for the children? WOMAN: No, but it uses a lot of petrol, so I’m spending far too much money on it. MAN: Oh, I...

MAN: I've always wanted to work in the movie business. WOMAN: The movie business? You mean you want to become a famous actor? MAN: No, something more behind the camera. WOMAN: Like a producer? You want to be in charge of all those people? MAN: Not really. I love telling stories. I would love to...

MAN: One day, I'd love to live by the sea. WOMAN: Really? I’m quite happy in my flat. It’s in town, but it’s quiet. MAN: But wouldn’t you like to live out in the country? WOMAN: One day, maybe. Perhaps even up in the mountains. Two friends are talking about homes. Where does the woman live...

Father: What was that music you were listening to? Are you seriously calling that music? Daughter: What do you mean? Are you kidding? You just don't understand today's music. Father: I know what's considered good quality and I just don't think that qualifies. Daughter: But it's fresh and...

MAN: So how was your day at college? WOMAN: It was good! We had to give a talk about our most nerve-wracking experience ever! MAN: Go on then – what was yours? WOMAN: You remember when we did ‘Romeo and Juliet’ back in Year 6? MAN: Yes, of course - you were brilliant. WOMAN: I was absolutely...

Man: So you're working at the university now? What do you teach? Woman: I teach English literature. It's a required course for all. Man: Wow. That sounds like it could be a lot of work! Woman: It definitely keeps me busy. If I'm not teaching, I'm grading papers or meeting with students. They...

MAN: It was the long hours that took it out of me initially. I was shattered after a day’s work. WOMAN: Well, for me, the thrill of it all, you know, working in a radio studio, kept my energy levels up. MAN: I can understand that. I guess I just wasn’t used to that kind of timetable. WOMAN...

I work for a web-based outfit – a very professional setup indeed, I’ve discovered, with several freelancers on the books and four in-house writers, me being one. The website itself is striving to build its name and I suppose that’s what led to my being headhunted really. They knew my work well...

Fiona Singleton is only eleven years old and she is already a brilliant pianist. However, she lives in $..........$ a small flat that there is certainly no room for a piano. So, every single day after school, Fiona rides the bus across town to see her aunt, whose grand piano is always available...

Hi there. It’s Mary. Sorry, bit of a weird one. I forgot to take the lamb out of the freezer for the dinner party this evening and now it’s too late. I’m a total disaster! Anyway, I was listening to that cookery programme on the radio, you know, the one I love with that guy from the telly, and...

MAN: That was a shame about the charity night – I was really looking forward to it. WOMAN: Yeah, I couldn’t believe it when that guy got on stage and he’s like, ‘Sorry, the band hasn’t turned up.’ MAN: Yeah, ‘You’ve all got to go home, the singer’s got his dates mixed up’. Unbelievable! Then...

I want to tell you about what I did last month. As part of my marine biology course, I got a two-week placement with a team of researchers who are studying dolphins off the east coast of Scotland. As we all know, species like dolphins are finding it increasingly difficult to survive, thanks to...