1/ The most disastrous earthquake in Japan, which occurred in 1923 killed about 150,000 people.

2/ The planet which is closest to the Earth is Venus.

3/ The animal which was closen to be the logo of Sea Games 2003 is the buffalo.

4/ The explorer who discovered America was Christopher Columbus.

5/ Pompeii was completely destroyed in AD 79 by an eruption of Mount Vesuvius.

6/ It snowed in Lang Son in the winter of 2002.

7/ Typhoon, hurricane, and cyclone are different words for the same matural disaster.

8/ They saw a lot of interesting buildings about their sight seeing trip.

9/ He was thought breaking the window last week.

10/ Everybody loves him because of his politeness.

cái này nó dạng kiểu phân số nhưng k biết kẻ đường kẻ ở dưới

Giải:

Gọi chiều dài khu vườn hình chữ nhật là x (m: x >4)

Gọi chiều rộng khu vườn hình chữ nhật là y (m: x >y >0)

Diện tích khu vườn hình chữ nhật là x.y \(\left(m^2\right)\)

Nếu giảm chiều dài đi 4m, tăng chiều rộng lên 4m thì diện tích của khu vườn tăng thêm 32\(m^2\) nên ta có phương trình:

\(\left(x-4\right).\left(y+4\right)=xy+32\)

\(\Leftrightarrow xy+4x-4y-16=xy+32\)

\(\Leftrightarrow4x-4y=48\)

\(\Leftrightarrow4\left(x-y\right)=48\)

\(\Leftrightarrow x-y=12\) (1)

Nếu giảm chiều dài đi 4m, tăng chiều rộng lên 2m thì diện tích giảm 88\(m^2\) nên ta có phương trình:

\(\left(x-4\right).\left(y+2\right)=xy-88\)

\(\Leftrightarrow xy+2x-4y-8=xy-88\)

\(\Leftrightarrow2x-4y=-80\)

\(\Leftrightarrow2\left(x-2y\right)=-80\)

\(\Leftrightarrow x-2y=-40\) (2)

Từ (1) và (2) ta có hệ phương trình:

\(\left\{{}\begin{matrix}x-y=12\\x-2y=-40\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}y=52\\x-y=12\end{matrix}\right.\)

\(\Leftrightarrow\left\{{}\begin{matrix}y=52\left(TMĐK\right)\\x=64\left(TMĐK\right)\end{matrix}\right.\)

Vậy chiều dài khu vườn hình chữ nhật là 64m

chiều rộng khu vườn hình chữ nhật là 52m

diện tích khu vườn khu vườn hình chữ nhật là 64.52=3328 \(\left(m^2\right)\)

Identify the one underlined word or phrase. A, B, C or D - that must be changed for the sentence to be correct.

My shoes were so uncomfortable that I had to go out and buy  new one

A. so

B. had to

C. and buy

D. one

The company's director lacks lead skill

The company's director lacks (lead) skill

khi đó x+y=10

1) The teacher is wearing a blue jacket. He teaches us mathematics.

--> The teacher who teaches us mathematics is wearing a blue jacket.

2) The garden is watered every morning. It is full of flowers.

--> The garden which is full of floewrs is watered every morning.

3) The dog is sitting on the chair. It is wild.

--> The dog that is wild is sitting on the chair.

4) The book is lying on the bookshelf. It is about geography.

--> The book which is about geography is lying on the bookshelf.

5) The computer is breaking down. It is an old one.

--> The computer which is an old one is breaking down.

6) The flowers are grown in this garden. They are fresh.

--> The flowers which are fresh are grown in this garden.

7) The sofa is put in the living room. It is new.

--> The sofa which is new is put in the living room.

8) The man holding a bunch of flowers. The man is my best friend.

--> The man who is my best friend holding a binch of flowers.

Khúc cuối không cần cắt nên chỉ cần cắt 99 lần

Vậy cắt xong khúc vải đó mất : 99 * 5 = 945 ( giây ) 

đề là j z