Câu 7:

a, Dấu phẩy thứ nhất dùng để: Đánh dấu ranh giới giữa các từ có cùng chức vụ trong câu (cụ thể là ranh giới giữa hai trạng ngữ thời gian và nơi chốn)

b, Dấu phẩy thứ hai dùng để: Đánh dấu ranh giới giữa các thành phần phụ với chủ ngữ, vị ngữ trong câu.

Vì em cần bài 7 nên anh làm bài 7 thui hi ^^ Em xem có gì không hiểu thì hỏi lại nha!

POP POP  THANK YOU :3P

a,Cứ 1 giờ xe A đi được: 1:15 = \(\dfrac{1}{15}\) (quãng đường AB)

Cứ 1 giờ xe B đi được: 1 : 12 = \(\dfrac{1}{12}\)( quãng đường AB)

Thời gian hai xe gặp nhau là: 1: (\(\dfrac{1}{15}\)+\(\dfrac{1}{12}\)) = \(\dfrac{20}{3}\) (giờ)

Đổi \(\dfrac{20}{3}\) giờ = 6 giờ 40 phút

Hai xe gặp nhau lúc: 

6 giờ 30 phút + 6 giờ 40 phút = 13 giờ 10 phút

b, Sau 6 giờ hai xe đi được: (\(\dfrac{1}{15}+\dfrac{1}{12}\))\(\times\)6 = \(\dfrac{9}{10}\)(quãng đường AB)

48 km ứng với phân số là: 1 - \(\dfrac{9}{10}\) = \(\dfrac{1}{10}\)(quãng đường AB)

Quãng đường AB dài: 48 : \(\dfrac{1}{10}\) = 480 (km)

Đáp số: a, 13 giờ 10 phút

             b,  480 km

(\(x+1\))+(\(x+2\))+...+(\(x\) + 211) = 23632

(\(x\) + \(x\)+...+\(x\)) + (1 + 2 +...+211) = 23632

Xét dãy số: 1; 2; 3; ...;211 đây là dãy số cách đều với khoảng cách là:

2-1= 1

Số số hạng là: (211- 1):1 + 1 = 211 (số)

Ta có:

\(x\) \(\times\) 211 + ( 211 +1)\(\times\)211 : 2 = 23632

\(x\times\) 211 + 22366 = 23632

\(x\times211\) = 23632 - 22366

\(x\times\) 211 = 1266

\(x\) = 1266 : 211

\(x\) = 6 

Em cảm ơn ạ

2. No other runner is quicker than her.

3. She makes fewer mistakes than last time.

5. Jurassic Park was directed by Steven Spielberg.

8. The last time John did housework was a month ago.

Số số hạng của vế trái là :

  (a - 1) : 1 + 1 = a (số hạng)

Suy ra : \(\dfrac{\left(a+1\right)a}{2}=4095\), từ đó :

\(\left(a+1\right)a=4095\) x \(2=8190\)

Ta có :  90 x 91 = 8190 nên a = 90

                           Đ/s : 90

Hello everybody . Today, I'm very happy to talk about myself. My name is Vy. I'm 12 years old . I live in Son Hoa village . I go to Nguyen Khac Vien secondary school and i'm in class 7C . It is the best class of grade 7 . I like English best because it is very interesting and fun . After school , I often play badminton with my best friend . In my free time , I usually help my mom or watch TV . That's all , I want to talk about myself . Thanks for listening

Topic 3 :

At twenty-five past nine, the bell rings and all the students do into the yard. It is time for recess. They are all happy and excited. They meet their friends and have some fun. Many are talking about the last class, or last night's movie. Som are eating and drinking as well as chatting. Some students are playing gameslike blindman's bluff or catch. Some boys are playing marbles and some girls are skipping rope. But the most popular activity is talking. The yard is very noisy until the bell rings. Then everyone goes indoors and classes begin again.

My name is Huy. I am twenty-four years old. I live in Ho Chi Minh city in the south of Vietnam.I’m a generous and easy-going person but when it comes to work I’m a competitive perfectionist. I’m also an optimistic and outgoing person so I have many friends and other social relationships. I enjoy reading, writing and doing math. I decided to become a Civil Engineer because I have always been fascinated by bridges, buildings, and skyscrapers. A degree in Civil Engineering enables me to achieve my goals and also gives me an opportunity to make a difference in the community.

Five years from now, I want to become a project manager of a construction project. As a project manager, my primary goals are managing people, set budgets, and making decisions of all kinds. I also want to speak English fluently so I can work with people from different countries.