= 80.25

15.12+65.13=180+845=1025

đề bài thấy hơi sai sai đấy

Bài làm:

\(A=\frac{3^4.2^3-3^4.4}{3^5.3^2-3^5.5}\)

\(A=\frac{2^2.3^4\left(2-1\right)}{3^5\left(3^2-5\right)}\)

\(A=\frac{4.1}{3.4}=\frac{1}{3}\)

Bài làm 

\(A=\frac{3^4.2^3-3^4.4}{3^5.3^2-3^5.5}=\frac{3^4\left(2^3-4\right)}{3^5\left(3^2-5\right)}\)

\(=\frac{81.2}{243.4}=\frac{81}{243.2}=\frac{81}{486}=\frac{1}{6}\)

Bài làm 

\(2x+\frac{69}{2}=69.4\Leftrightarrow\frac{4x}{2}+\frac{69}{2}=\frac{552}{2}\)

\(\Leftrightarrow4x+69=552\Leftrightarrow4x=483\Leftrightarrow x=\frac{483}{4}\)

\(\frac{6}{2x+2}=\frac{3}{3x-15}ĐK:x\ne-1;3\)

\(\Leftrightarrow\frac{18x-90}{\left(2x+2\right)\left(3x-15\right)}=\frac{6x+6}{\left(3x-15\right)\left(2x+2\right)}\)

\(\Leftrightarrow18x-90=6x+6\Leftrightarrow12x-96=0\Leftrightarrow x=8\)TM điều kiện 

A=\(\frac{4}{5}\)+(\(\frac{1}{5}-\frac{1}{7}\))x\(\frac{2}{7}\)=\(\frac{4}{5}+\frac{23}{35}\)x \(\frac{2}{7}\)=\(\frac{4}{5}+\frac{46}{245}\)=\(\frac{242}{245}\)

=\(\frac{4}{5}+\left(\frac{1}{5}-\frac{1}{7}\right)x\frac{2}{7}\)
=\(\frac{4}{5}+\frac{1}{5}-\frac{1}{7}x\frac{2}{7}\)
=\(\frac{4}{5}+\frac{1}{5}-\frac{2}{49}\)
=\(1-\frac{2}{49}\)
=\(\frac{47}{49}\)
2 cách bạn xem cách nào đúng thì k nha hihi

1. Which mountain is the highest in the world? How high is it? Where is it?

- The highest mountain in the world is Mount Everest - 8.848 metres and it's located in Nepal and Tibet.

2. What are the shortest words in English?

- The shortest words in English are "a" and "I".

3. Which river is the longest river in the world?

- The Nile River.

4. Which country is bigger: The United Kingdom or France?

- It's France.

5. Which metal boils at higher temperature: gold or silver?

-  It's gold.

1. How far is it from the earth to the moon?

2. The children are playing football in the schoolyard at the moment.

3. There is an interesting film after the news programme on TV.

4. It usually takes him half an hour to go to school by bicycle.

5. Would you to go to the cinema with me?

1. How far is it from the earth to the moon?

2. The children are playing football in the schoolyard at the moment.

3. There is an interesting film after the news programme on TV.

4. It usually takes him half an hour to go to school by bicycle.

5. Would you to go to the cinema with me?

Bài làm 

\(\frac{12}{-21}=\frac{-28}{x}\Leftrightarrow12x=588\Leftrightarrow x=49\)

1. Shall we go to the zoo ? => Let's go to the zoo !

2. Hoa's school has a lot of students => There are a lot of students in Hoa's school. 

3. Miss Lan is good English teacher => Miss Lan teaches English well. 

4. Her book is not the same as mine => Her book is different from mine.

5. Our address is 10 Hang Bong street => We live at 10 Hang Bong street.

6. Apples are usually cheaper than oranges => Oranges are usually more expensive than apples.

7. A play is often longer than a film => A film is often shorter than a play.

8. He drives faster than I do => He is a faster driver than I'm.

9. I will introduce you to my best friend if you => Shall I introduce you to my best friend.

10. It's very hard for the children to live independently => To live independently is very hard for a children.