1 phân = 1cm

Nhà bác học đó đã nhắc đến ĐÒN BẪY. Nhà bác học đó là Ác - si - met

trong các máy cơ đơn giản thì Đòn bẫy mới có điểm tựa.Nên nhà bác học đó nhắc đến Đòn bẫy. Nhà bác học đó là Asimet

Trong các chất khí : oxi, hidro và cacbonic thì

A. hiđro dãn nở nhiệt nhiều nhất

B. cacbonic dãn nở nhiệt ít nhất

C. ôxi dãn nở nhiệt như hidro

D. cả 3 đều dan nở nhiệt như nhau (Đáp án đúng là D)

-Vì x² \(\ge\) 0 \(\Rightarrow\) x² + 2 \(\ge\) 2

-Vì y⁴ \(\ge\) 0 \(\Rightarrow\) y⁴ + 6 \(\ge\) 6

\(\Rightarrow\) (x² + 2)(y⁴ + 6) \(\ge\) 12

Vậy không có cặp số (x; y) nào thỏa mãn (x² + 2)(y⁴ + 6) = 10

Ta có:

2A = \(\frac{2\left(2^{2017}+1\right)}{2^{2018}+1}\) = \(\frac{2^{2018}+2}{2^{2018}+1}\) = \(\frac{2^{2018}+1+1}{2^{2018}+1}\) = \(\frac{2^{2018}+1}{2^{2018}+1}\) + \(\frac{1}{2^{2018}+1}\) = 1 + \(\frac{1}{2^{2018}+1}\)

2B = \(\frac{2\left(2^{2018}+1\right)}{2^{2019}+1}\) = \(\frac{2^{2019}+2}{2^{2019}+1}\) = \(\frac{2^{2019}+1+1}{2^{2019}+1}\) = \(\frac{2^{2019}+1}{2^{2019}+1}\) + \(\frac{1}{2^{2019}+1}\) = 1 + \(\frac{1}{2^{2019}+1}\)

Vì \(\frac{1}{2^{2018}+1}\) > \(\frac{1}{2^{2019}+1}\) \(\Rightarrow\) 1 + \(\frac{1}{2^{2018}+1}\) > 1 + \(\frac{1}{2^{2019}+1}\) \(\Rightarrow\) 2A > 2B \(\Rightarrow\) A > B

Vậy A > B

1 What are you going to play this Sarturday?

I'm going to play tennis this Saturday.

2 Where do your sister and her family live ?

My sister and her family live on Tran Phu street

3 How much chese is there in the fridge ?

There is some chese in the fridge.

4 How many eggs do you want for your breakfast?

I want three eggs for my breakfast.

5 What time do they often have dinner?

They often have dinner at eight in the evening.

6 How often does she go to the movie?

She goes to the movie once a week.

Correct the mistakes in these sentencer

1 My brother is going the market with me.

going the market \(\rightarrow\) going to the market

2 We are going to have a little eggs in lunch.

in \(\rightarrow\) for

3 Don't to talk in class.

to \(\rightarrow\) \(\varnothing\)

4 Is he teach you English?

is \(\rightarrow\) does