A = 2011+2012+2013+2014+2015+2016+2017+2018+2019

A = (2011+2019)+(2012+2018)+(2013+2017)+(2014+2016)+2015

A = 4030+4030+4030+4030+2015

A = 4030×4+2015

A=16120+2015=18135

A =16120+2015=18135

Chu vi căn phòng hình chữ nhật bằng: 2 . (10 + 6) = 32 m.

Do đó, chu vi căn phòng hình vuông cũng là 32 m.

Căn phòng hình vuông có chiều dài cạnh bằng: 32 : 4 = 8 m.

Căn phòng hình vuông có diện tích bằng 8 . 8 = 64 m2

-20123 > -20213

Topic 1

Hi Quan,

My family is very happy this year. The whole family wrapped Chung cakes, decorated the peach tree, cleaned the house. I helped my mother cook and go to the flower market. Everyone also went to wish our grandparents a happy new year and received lucky money. The happiest thing was that the whole family watched Tao Quan together.

Wishing Quan and your family a happy new year!

Best regards,

Minh

1. I / want / visit / Phu Quoc / because / the beaches / be / beautiful.
→ I want to visit Phu Quoc because the beaches are beautiful.
2. There / be / new / movie theatre / my neighbourhood.
→ There is a new movie theatre in my neighbourhood.

1. This shirt is cheaper than the jacket.
   → The jacket is more expensive than this shirt.
2. It’s not a good idea for you to sweep the floor on the first day of Tet.
   → You shouldn’t sweep the floor on the first day of Tet.
3. How about spending time at the new park?
   → Let’s spend time at the new park.