I live in the suburbs in Thai Nguyen City. There are many things I like about my neighborhood. It's great for outdoor activities because it has a new beautiful park and the weather is good. There's almost everything I need here: shops , restaurants, supermarket and cinema. The people here are helpful and friendly. The food is delicious. However, there are three things I dislike about it: the school is far from my house, No beach and the street are busy, crowded day and night

1. → 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.

1. → 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.

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

Nhận thấy đây là 9 số tự nhiên liên tiếp, số ở giữa là 2015.

Vậy tổng bằng:

\(A = 2015 \times 9 = 18135\) \(\boxed{A = 18135}\)

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`

\(A = 4030 \times 4 + 2015\)

\(A = 16120 + 2015 = 18135\)

• \(\mid - 20213 \mid = 20213\)
• \(\mid - 20123 \mid = 20123\)

Vì \(20213 > 20123\) nên:

\(\boxed{- 20213 < - 20123}\)