\(\frac{21^2.14.125}{35^5.6}=\frac{\left(3.7\right)^2.2.7.5^3}{\left(5.7\right)^5.2.3}=\frac{3^2.7^3.2.5^3}{5^5.2.3.7^5}=\frac{3.}{5^2.7^2}=\frac{3}{1225}\)

b,

\(\frac{72^3.54^2}{108^4}=\frac{\left(2^3.3^2\right)^3.\left(2.3^3\right)^2}{\left(2^2.3^3\right)^4}=\frac{2^{11}.3^{12}}{2^8.3^{12}}=2^3=8\)

Ai là sky thì tick cho tui nha,ko tick ko phải là sky của sếp Tùng.

Diện tích hình chữ nhật  là:

18x13=234(cm²)

1.A new shirt has been bought for her daughter.

2.I've read a book which is about two school boys.

3.He used to smoke a lot.

4.I have just been phoned.

5.I passed the exam which made my parents proud of me easily.

hì 6:2(1+2)=6:2x3

                 =3x3=9

Ex1:

My mother likes fish

my father likes vegetables and meat

my sister likes sanwich....

I likes noodles/hamburger,...

My father has a cup of coffee

yes,he does

yes,I do

Ex2:

How much does a kilo of rice cost? It's 8000 dong

How much does a fried rice cost? It's 25000 dong

How much does an ice-cream cost? It's 9000 dong

How much does a bowl of noodles cost? It's 12000 dong

How much does a dozen of eggs cost? It's 440000 dong

VI:

1.what does he often do in the evening?

2.what is she praticing?

3.when do you usually play soccer?

4.how long wil you stay there?

5.who does Minh go swimming with?

6.who do you wait for everyday?

7.where is the children?

8.what subject does he have on Monday and Thursday?

9.what does she buy at the store?

10.how far is it from your house to the market?

(Bài đọc đoạn văn):

1. aT bF c F dT

2.a.usually

b.they often get together and talk about their stamps

c.yes,they do

d.no,I don't

XII(Bài viết đoạn văn)

suggeted:

-what is your school's name

-where is your school

-how does your school look(school gate,school yard,...)

-how many building,what color are those buildings?

-what about students(study good,hard working,friendly,hospitable)

-how do you see your school(good or not,love or not)

I:1.every 2.third 3.timetable 4.soccer 5.homework

II:1D 2A 3D 4A 5B 6A 7D 8B 9C 10C

11A 12D 13B 14B 15B 16D 17B 18B 19B 20C

III:

1.will they do/will listen

2.Can your brother swim/swims

3.is/to sit

4.doesn't do/wil do

5.is flying/will land

IV:

1.in/in

2.between

3.of/of

4.to/on/to/at

5.with

V:

1.beautiful

2.businessman

3.ninth

4.jogging

5.toothache

VI:

1.are => is

2.rides=>is riding

3.some =>any

4.many =>much

5.buying => to buy

6.go => wil go

7.play games usually =>usually play games

8.cold => hot

9.season => seasons

10.gram =>grams

VII:

from/do/much/the/don't/eat/in/at/on/look

VIII:

1.where can you go to buy beef?

2.who does Lan go to school with?

3.How often do they go to the zoo?

4.what would you like?

5.how long wil she stay there?

6.what do your daughters do every morning?

7.how much is this bar of soap?

8.what color is his pencil?

9.where is Lan going to live?

10.how many enghlish books do you want?

IX:BDCEGFHAI

Question I:1A 2B 3C 4A 5D

Question II:1B 2D 3D 4B 5C

Question III:1A 2D 3B 4C 5B 6D 7D 8D 9A

10B 11C 12B 13A 14A 15A

Question IV:

1.is cooking

2.does your mother go

3.is sleeping

4.isn't/doesn't want

5.is flying/will land

6.wil feel

7.am going to have/to come

Question V:

1.dangerous

2.beautiful

3.famous

4.knives

5.worrking

6.sunny

7.himself

8.careless

9.speaking

10.policeman

IV:1B 2B 3A 4C 5C

Question V:

1.homeworks=>homework

2.aren't =>don't

3.stands =>is standing

4.garden big => big garden

5.to =>for

6.have => has

7.gram => grams

8.does => do

9.staying => stay

10.any => some

Question VI:

1A 2C 3D 4B 5A 6C 7D 8D 9A 10C

English

Theo quan điểm tiến hoá hiện đại, trong khí quyển của Trái Đất nguyên thuỷ không có khí nào sau đây?

A.  H 2

B. Hơi nước

C.  O 2

D.  NH 3

1.Her computer is different from mine.

2.The country doesn't as modern as the city.

3.This book is the same as that one.

4.I spent as much money as Sarah.

5.Ho Chi Minh City is different from Ha Noi City.

6.Teddy is the youngest player in the orchestra.

7.In my job,Monday is the busiest day in the week.

8.My hair isn't as fair as my sister's hair.

ta có: (x+y+z)²=0
\(\Leftrightarrow\)x²+y²+z²+2(xy+z+xz)=0
\(\Leftrightarrow\)1+2(xy+yz+xz)=0
\(\Leftrightarrow\)xy+yz+xz=\(\frac{-1}{2}\)
lại có x².y²+y².z²+x².z²=(xy+yz+xz)²-2xyz(x+y+z)=\(\frac{1}{4}\)
\(\Rightarrow\)x⁴+y⁴+z⁴=(x²+y²+z²)²-2(x².y²+y².z²+x².z²)=\(1-2.\frac{1}{4}\)=\(\frac{1}{2}\)
vậy x⁴+y⁴+z⁴=\(\frac{1}{2}\)
(tick nka)