a. P(2) = | 2.2 - 3 | + | 2 . 2 + 5 | = 1 + 9 = 10 
P(-1) = | 2.(-1 )- 3 | + | 2 .(-1 )+ 5 | = 5 + 3 = 8 
b. GTNN bằng 8 

1. Go Green is a non-profit      organization   that protects the environment. (organise)

2. Many people were homeless           after the flood. (home)

3. We talked to and sang for the    elerly          people at a nursing home.(old)

4. the campaign           encourage           people to recycle glass, cans and paper.(courage)

5. The children volunteered to clean up their    neighbourhood          and local area( neighbour)

6. there are many kinds of         environmental        pollution such as air pollution, land pollution and water pollution(environment)

7. We've          donated         books and clothes to the children in remote areas.(donation)

8. The programme was    benifit   to both the community and individuals(benefit)

9. We've worked together for several months to provide good facilities for   unable           people.(able)

10. this project has been funded by         volunteering     contributions.(volunteer)        

X-1 thuộc B(6)={0;6;12;18;24;30;36;...}

=> X thuộc {1;7;13;19;25;31;37;...}

Mình đã làm rồi , giờ mình giải thích nhé !
1. go out with đã là một cụm đi chung với nhau nhé . 
Look after = take care of ( phr verb ) = quan tâm , chăm sóc 
2. Waiting for là bắt buộc nhé , waiting chỉ đi vs giới từ for thôi 
at the station vì đây là chỉ địa điểm . Không dùng in được vì in " chỉ một khoảng không gian "
3. is one of + plural noun ( ngữ pháp nhé ! )
Như đã nói dùng in để chỉ " một khoảng không gian " in the south = ở miền nam 
4. I am looking for , look for có nghĩa là tìm kiếm bằng động từ " find " 
5 . đã nới rồi nhé !
6 . ta có : S + be + good at + V-ing 
( giỏi về cái gì đó ) 
7 . interested in sth = like sth
8. fond of = like = carry on = interested in 
9 . on foot là chắc chắn nhé , next to luôn đi chung nhé 
10 . nếu chỉ ngày + tháng + 5 thi dùng preposition "on "
11 . như đã nói chỉ một mốc thời gian dùng in 
12. on + Month 
13 on + thứ ngày 
14. listen to là bắt buộc 
15. on hay at đều được , chỉ một địa điểm chính xác . 
16 . is on nhé , để chỉ bề mặt , và đây là đường 
17 . on để dùng chỉ các tầng , hay nới là để chỉ " bề mặt "
 

1.I cannot go out with you tonight because I have to look after my little brother

2. She's waiting for her friend at the station.

3. Vietnam is one of eleven countries in the south East Asia

4.What are you doing under the table? I am looking for my pen

5. She helps me to take care of my son when I am busy.

6. Are you good at playing badminton?

7. He is interested in reading detective stories.

8. I am fond of cooking but I am bad at. cooking

9. He usually travels to school on foot because his house is next to.... his school

10. My brithday is .......on. 27th May

11. She was born ....in...... 2001 

12. It is hot .........in.... June 

13. I don't go to school .....on.. Sundays

14. Listen .....to........ your teacher carefully 

15.She lives ........on..... 20 Ngo Quyen Street 

16. Her office is at Hang Bai Street < là sao bạn >

17.His apartment is ..........on.... the second floor

10 nam

Câu 5 số 2 là : What animal don't they like much nhé !

1. I am 20 years old.
Are you 20 years old ?
How old are you ?

2. She met him yesterday.
Did she meet him yesterday ?
Who did she meet yesterday?

3. They like playing football.
Do they like playing football?
What do they like ?

4. It is 5km from my house to my school.
Are there 5km from your house to your school?
How far is it from your house to your school ?

5. They don't like dog a lot.
Do they like dog ?
What animal do they don't like much ?

6. She can speak English well.
Can she speak English well ?
what language can she speak well ?

7. You are a student.
Are you a student ?
What are you ?
8. She loves Nam.
Does she love Nam ?
Who does she love ?
9. He often plays football in her free time.
Does he often play football in his free time ?
WHat sport does he play in his free time ?
10. There are 10 people in my family.
Are there 10 people in your family ?
How many people in your family ?

They met their friends yesterday.
=> Who did they meet yesterday ?