5x5-5=20

5:5x5=5

5:5x5:5x5x5=25

5 x 5 - 5 = 20

5 + 5 - 5 = 5

5 x 5 + 5 - 5 + 5 - 5 = 25

1.        From: Jenny

       To: Eric

       Subject: About my family members

       Hi Eric,

       Long time no see you. How are you? How about the first exam you did at school?

     Tet holiday is the biggest and the most important festival in VietNam. Tet often falls between late January and early February. Before Tet, my mother and I go shopping to buy clothes, candies, flowers, fruits and decorative items. My family always cleans and decorates our house together. On the first day of Tet, I don’t go out, I stay at home and sit around the pot of Banh Chung to talk, watch fireworks with my family. On the second day, I go to my grandparents’s house with my family and they give me lucky money. It’s always a nice day because I like to meet my grandparents so much! Next, on the third day, I visit my teachers and send them New Year wishes. And my favorite most is get the lucky money from the older because it brings me lucks in the year! How do you fell about Tet? Write me soon!

      Best,

       Jenny

TICK VÀ LIKE CHO MÌNH NHA MÌNH CẢM ƠN. THANKS

5,9 23,6 0,25 590 1180 0

12  -3 = 9

7 + 9 = 16

3 + 8  =11

3 + 5 + 8 = 8 + 8 = 16

4 + 7   - 6  = 11 - 6  = 5

12 - 3 =9

7 + 9 = 16

3 + 8 = 11

3 + 5 + 8 = 16

4 + 7 - 6

= 11 - 6

= 5

(-37)+14+26+37

=(37-37)+(14+26)

=0+40

=40

(-37) + 14 + 26 + 37

= [(-37) + 37] + 14 + 26

= 0 + 14 + 26

= 14 + 26

= 40

A => are

2 -  2  = 0

Choose A

-> To put a large amount of information on a map, a variety of symbols are used.

A => to put

owns - only uses

Lời giải:
Diện tích nền nhà: $40\times 10=400$ (m²)

Đổi $400$ m² = $40000$ dm²

Diện tích 1 viên gạch: $5\times 5=25$ (dm²)

Cần số viên gạch để lát nền là: $40000:25=1600$ (viên) 

Số tiền mua gạch: $1600\times 15000=24000000$ (đồng)