vì a+b/b+c = c+d/d+a nên

(a+b).(d+a) =(c+d).(b+c)

ad+bd+bd+ab=cb+db+db+dc

ad+ab=cb+dc (  2 vế cùng bớt đi db+db)

a.(d+b)=c.(b+d)

=> a=c

My best friend is Lan. We have known each other since we were 10 years old. However we became best friends when we were at grade 7. Now she lives with her parents in Nguyen Trai street.

She has long black hair a straight nose and a small pointed chin. She is quite slim. She doesn t like to dress up so I usually see her wearing jeans and a T - shirt

What I like about Lan is that she has same hobbies with me. We are so lucky that we get along so well. I hope that our friendship can last long.

Tet holiday is the special days in Vietnam. It's time to each family remember their ancestors.

Before Tet comes, my family as well as others, we always do house works to welcome a new year appears. Besides, Chung or Tet is the traditional cake of Vietnam. Chung presents for the North, and Tet features for the South and the middle. We stay overnight to cook cake and talk about a previous year, review the memorable moments before that. This time is so special. At 00h o'clock, everybody countdown to say happy new year. My morther usually worship to invite ancestor come home. eveybody call eachother to wish a year with happy, success, health.

after, we go to the others family or ralative relationship to visit eveyone in Tet holiday. we take the blossom or cherry flower to decorate our house to sake up luck.

My aunt goes to the drug store to get some medicine.

My best friend is Lan. We have known each other since we were 10 years old. However we became best friends when we were at grade 7. At that time I was very bad at English and it was who helped me improve my English. Now she lives with her parents in Nguyen Trai street.

If I were to describe how she looks I would say she is very pretty. She has long black hair a straight nose and a small pointed chin. She is quite slim. She doesn t like to dress up so I usually see her wearing jeans and a T - shirt. She has a very nice personality and a wonderful sense of humour but she can also get a little depressed from time to time. I can always count on her to be honest and to give me the best advice.

What I like about Lan is that she has same hobbies with me. We both enjoy singing karaoke reading comic books and going shopping. We like going to the cinema but sometimes can t agree on which movie to see. In addition since I am better in Maths and Chemistry and she is better in English and languages we can always help each other if we get confused about a difficult homework assignment. We are so lucky that we get along so well. I hope that our friendship can last long.

Nửa chu vi mảnh đất hình chữ nhật là: 70 : 2 = 35 (m)

Tổng số phần bằng nhau là: 3 + 4 = 7 ( phần)

Chiều dài mảnh đất hình chữ nhật là: 35 : 7 x 4 = 20 (m)

Chiều rộng mảnh đất hình chữ  nhật là: 35 : 7 x 3 = 15 (m)

Diện tích mảnh đất hình chữ nhật là: 20 x 15 = 300 (m²)

Đáp số: 300 m²

1. Tell about the benefit of TV

Tevision can be used for entertainment as well as educational uses. You may already be aware of some of the benefits you get out of television. Television broadcasts the news and weather stations to keep you up to date on the current events. This is a very good benefit since a person needs to know what happens around them. Television can be very educational for the watcher. They can learn new things through educational programs and from TV in general.he television makes for great family bonding. It allows a family to watch a show or movie together and share a great time together. Complex TV shows or movies require a great deal of intelligence to understand the show or movie. The television brings in different kinds or people and cultures into your family room, such as the Travel channel and the Food Networking channel. elevision brings in many different things into the family room and gives people many different things to talk about who have little in common. The television is really good at informing the viewer how to do things. With the different reality TV shows, it makes for great entertainment. Television makes exercising a lot easier.Many drama shows require you to remember the plot from week to week. This will allow you to get the most out of the shows.

Now he is going to the coutryside with his son,Nam

1. My friends hate eating out. They think it costs a lot of money.

2. My parents like living in the countryside.

3. They have moved to our hometown for 2 years.

4. My brother usually goes Fishing in his free time.

5. we do not like roller skating because it's dangerous.