Khi mà nhiệt độ của chất có thể đang sôi hoặc đang nóng chảy và đông đặc. Mà băng phiến có nhiệt độ nóng chảy (hay đông đặc) ở 80 độ C nên chất này chính là băng phiến

P/S : Good Luck
~Best Best~

1.

My school is ten kilometers away from my home, and I go by the school bus every morning. I love to go to school. I learn so many new things at school every day. There are many different subjects I study at school. I study languages like Sanskrit, Hindi and English, and other subjects like mathematics, science and social studies.

My school is very beautiful. There are nice, lush gardens with beautiful plants and trees. In spring time the blooming flowers are a spectacle. My school has a well equipped library, and I enjoy reading books. There are also computers in the school for our use.

I love my school and my teachers. My teachers are very caring. They teach us with a great deal of patience, and they want us to become good and responsible human beings. I want to make my school and my teachers proud of me.

2.

He was born in Văn Thôn village, Quang Liệt commune, present day Thanh Tridistrict, Hanoi. In the early life, he was famous as a straight forward man who passed the doctoral examination (Thái Học Sinh )but refused to become a mandarin. Instead, An opened a school and began his career as a Confucian teacher in Huỳnh Cung village in Thanh Tri. An's teaching played an important role in spreading Confucianism into a Buddhist Vietnam in this time.

Under the reign of Tran Minh Tong (1314–1329), he became a teacher at the imperial academy where he was responsible for teaching the crown prince Vuong, the future emperor Tran Hien Tong. Under the reign of emperor Tran Du Tong, he was raised to a high-ranking mandarin.

Later, he resigned and return to his home-village because Tran Du Tong refused his request of beheading eight other mandarins who he accused of corruption. For the rest of his life, An continued his teaching career and wrote books. He died of illness in 1370.

An altar was erected in his honour in the Temple of Literature in Hanoi, where he is still revered.

b) \(2\sqrt{x}=1\)

⇔ \(\sqrt{x}=1:2\)

⇔ \(\sqrt{x}=\frac{1}{2}\)

⇔ \(\sqrt{\frac{1}{4}}=\frac{1}{2}\)

=> \(x=\frac{1}{4}\).

Vậy \(x=\frac{1}{4}\).

Mình chỉ làm câu b) thôi nhé.

Chúc bạn học tốt!

tam vai thu 2 dai la : 

 80 - 50 = 30 (m )

ti so phan tram cua tam vai thu hai so voi tam vai thu nhat la : 

30 : 50 = 60 % ( tam vai thu nhat )

      Dap so : 60% tam vai thu nhat .

60 % so với tấm vải thứ nhất nhé bn

>_< chúc các bn học tốt

C.50 do vi doi dinh

B. 50 độ mới đúng. Bạn sai rồi

1a)

x+18 =2x+35

x-2x=35-18

-x=17

x=-17

1b)

x+80=-45-27

x+80=-72

x=-72-80

x=-152

1c)

-x-27=-2x+50

-x+2x=50+27

x=77

chiều rộng là 

  80 x 2 = 160 m

diện tích là 

  80 x 160 = 4800 m2

có số tạ thóc là

4800 : 100 = 4800 kg

   đổi 4800 kg = 48 tạ

            Đ/S : 48 TẠ THÓC

16 tạ thóc

a) 50% số m vải là: 1400  × 50  ÷ 100 = 700 (m)

b) 25% số m vải là: 1400  × 25  ÷ 100 = 350 (m)

c) 80% số m vải là: 1400  × 80  ÷ 100 = 1120 (m)

d) 75% số m vải là: 1400  × 75  ÷ 100 = 1050 (m)