vì có 31 số nguyên nằm giữa a và -a nên

a-(-a)=32

=>a+a=32

=>2a=32

=>a=32/2

=>a=16

Vậy a=16

x-10=200

x=200+10

x=210

8000 km

My future house will be a villa. It will located by the sea. It will surrounded by many tall trees. There will be ten rooms in the house: a living room, two bedrooms, two bathrooms, a kitchen, a dinning room, a gym, a library and a music room. In front of the house will be a big garden with many fruit trees and flowers. There will be a swimming pool and a big playground behind the house. To the left of the house will be a small pond where I can raise fish. My future house will have solar energy and wind energy. I will have two robots to help me do the houseworks such as: clean the floor, cook meals,....and a super smart TV to help me self- study at home, contact with my friends and order food from the supermarket.

I think I will live more comfortably and happily in my future house. I hope my dream will come true soon.

I.
1.___ Have____ you ever (see)__seen______ a real robot at work? - No, never
2.If the weather (be)___is____fine, we (plant)___will plant____ some young trees in our garden.

3.I (read)__have read_____that novel three times.

4. Maryam (stay)__is staying_________ with us at the moment.
II.read the passage and answer te questions.
In the summer holidays, Mr. Hung, Mrs. Lan and their children often go to Vung Tau for two or three days. They usually stay in a small house or a flat by the sea, but sometimes they stay in a hotel.
Last summer they went to Nha Trang. They stayed at the Sunshine Hotel for three days. In the morning, Ba played soccer with his father on the beach. Lan and her mother walked long the beach and built sand castles. They visited Tri Nguyen Aquarium. They also bought a lot of souvenirs for their friends.

1.Where does Lan's family often go for their summer vacation?
=> They usually go to Vung Tau for their summer vacation
2. How long do they often stay there?
=> They often stay there for two or three days
3. Where did they go last summer ?
=> They went to Nha Trang last summer
4.What did Lan and her mother do in the morning?
=> Lan and her mother walked long the beach and built sand castles.
5. Did they visit Tri Nguyen Aquarium ?
=> Yes, they did

III .Put the verbs in the brackets in the corect form.
1.______Have_______ you ever (see)___seen_____ a real robot at work ? -No, never
2.If the weather (be)______is_____fine , we (plant) __will plant__ some young trees in our garden.
3.I (read)_____have read_________that novel three times.
4.Maryam (stay) _is staying___with us at the moment.

1000 số

A=\(\frac{7}{10.11}\)+\(\frac{7}{11.12}+\frac{7}{12.13}+...+\frac{7}{69.70}\)

7A=\(\frac{1}{10.11}+\frac{1}{11.12}+\frac{1}{12.13}+....+\frac{1}{69.70}\)

7A=\(\frac{1}{10}.\frac{1}{11}+\frac{1}{11}.\frac{1}{12}+\frac{1}{12}.\frac{1}{13}+...+\frac{1}{68}.\frac{1}{69}+\frac{1}{69}.\frac{1}{70}\)

7A=\(\frac{1}{10}.\frac{1}{70}\)

7A=\(\frac{1}{700}\)

=>A=\(\frac{1}{700}:7\)

A=\(\frac{1}{4900}\)

Cuối năm 2010 số dân của huyện đó là:

125000 +(125000 x 1,6%)=127000 (người)

Cuối năm 2011 số dân của huyện đó là :

127000 +(127000 x 1,6%)=129032 (người)

Đáp số: 129032 người

Ai k mk mk k lại

\(A=\frac{7}{10.11}+\frac{7}{11.12}+\frac{7}{12.13}+...+\frac{7}{69.70}\)

\(A=7.\left(\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}+\frac{1}{12}-\frac{1}{13}+...+\frac{1}{69}-\frac{1}{70}\right)\)

\(A=7.\left(\frac{1}{10}-\frac{1}{70}\right)\)

\(A=7.\frac{3}{35}\)

\(A=\frac{3}{5}\)

Số bé nhất có hai chữ số là số 10