Hi Tom,
I hope this email finds you well. I wanted to share an exciting opportunity with you – the upcoming Ok Om Bok Festival! It's a vibrant and culturally rich event that celebrates the traditional harvest season.
Participating in the festival will give you a chance to immerse yourself in the local culture, witness mesmerizing rituals, and enjoy delicious traditional foods. The festival's colorful atmosphere and warm community spirit make it a unique experience.
Don't miss out on this fantastic cultural celebration! Your presence would undoubtedly add to the festive cheer. Looking forward to seeing you there!
Best regards,

Xuan Thanh

Dear Tom,

I'm happy to hear that you are going to join the Ok Om Bok Festival in Soc Trang Province. As I know, Ok Om Bok Festival, also called Moon Offering Festival is traditional folk festival has existed for a very long time of Khmer people in Mekong Delta, especially 2 Tra Vinh and Soc Trang Provinces. 

Here, I have some advice for you to dos and don'ts at that festival. First, I think you should wear trainer or shoes and comfortable clothes because maybe you must be walk a lot. And then, remember to bring some bottle of water, it will be hot in Soc Trang so you will get thirsty.

Also, I should remind you that you must not to litter on the ground or run away from your father. It's an big festival so it will be crowded, you should be careful to not get lost. Anyway, I hope you will have a great time with your dad and enjoy the festival.

I help my family in various ways to contribute to their well-being. Firstly, I assist with household chores such as cleaning, cooking, and doing laundry. This helps to lighten the workload for everyone and ensures a clean and comfortable living environment. Additionally, I offer my support and lend a listening ear whenever someone in my family needs to talk or share their problems. I also help with grocery shopping and running errands, making sure that everyone's needs are met. Lastly, I try to be responsible and respectful towards my family members, showing them love and appreciation. These small acts of kindness and assistance go a long way in creating a harmonious and supportive family dynamic.

I do several things to help my family on a regular basis. One of the most important ways I contribute is by taking on household chores. I help with tasks such as cleaning the house, doing the laundry, and washing the dishes. By taking responsibility for these chores, I alleviate some of the burden from my parents and ensure that our home remains clean and organized. Additionally, I assist with grocery shopping and meal preparation. I often accompany my parents to the supermarket, help them choose the items we need, and carry the bags back home. I also enjoy cooking and take pleasure in preparing meals for my family. This not only saves my parents time and effort but also allows us to enjoy delicious and healthy homemade meals together. Furthermore, I provide emotional support to my family members. I am always there to lend a listening ear, offer advice, or simply provide a comforting presence when someone is going through a tough time. I believe that being there for each other is crucial in maintaining a strong and loving family bond. Overall, I take pride in the various ways I contribute to my family's well-being and strive to make their lives easier and happier.

    Hùng King is a traditional festival in my country. It takes place on the tenth March every year, at Hi Cương area, Việt Trì town, Phú Thọ province. At this festival, the ticket cost is free for children whose tall is under 1m and 100,000 VND for everyone. You can join traditional competitions, eat traditional food or watch performance about Hùng King.

Hùng King is a traditional festival in my country. It takes place on the tenth March every year, at Hi Cương area, Việt Trì town, Phú Thọ province. At this festival, the ticket cost is free for children whose tall is under 1m and 100,000 VND for everyone. You can join traditional competitions, eat traditional food or watch performance about Hùng King.

My favorite hobby is playing badminton. I started about 2 years ago. I play badminton with my father everyday afternoon. I always play badminton at home. I think it is a sport very good for our health.

My favorite hobby is playing football. I started playing in the summer 2 years ago. I play football with my friends every afternoon. We always play football at home. I think it is a very good sport for our health.

Living in the countryside is very unique. Although many people think that the country is not good or not well-provided, it's still one of the best options for healthy living. In the countryside, first, it's the low cost of living. Secondly, unlike the cities, the country provides fresh air and green spaces. Last but not least, the villagers are always kind and friendly, willing to help each other no matter what.

Some people really prefer to live in the downtown because of its facilities. But I prefer to live in the countryside because of many reasons.

First of all, the life in the city makes me uncomfortable, I cannot bear to live in cramped conditions with the hustles and bustles. We do not have fresh air to breathe, do not have a space for our children to play and for us to relax. It is really tiring and upset to wait for hours because of traffic jams.

Secondly, the pollution because of smogs and dusts and noise can make me feel sick. Moreover, I do not feel safe to live in the city because the criminal situations are rising. , We feel worried when we go out each time.

Thirdly, Nowadays, the conditions of the countryside are better and better, the gap between the cities and the countryside is narrowed day by day.

I love the silence, I love fresh air. I love the good relationships of people. so I love to live in countryside.

Lời giải:

$3x^2+x=4y^2+y$

$\Leftrightarrow 4(y^2-x^2)+(y-x)=-x^2$

$\Leftrightarrow (y-x)[4(x+y)+1]=x^2$

$\Leftrightarrow (x-y)[4(x+y)+1]=x^2$

Gọi $d=(x-y, 4x+4y+1)$

Khi đó: $x-y\vdots d(1); 4x+4y+1\vdots d(2)$. Mà $x^2=(x-y)(4x+4y+1)$ nên $x^2\vdots d^2$
$\Rightarrow x\vdots d(3)$.

Từ $(1); (3)\Rightarrow y\vdots d$

Từ $x,y\vdots d$ và $4x+4y+1\vdots d$ suy ra $1\vdots d$

$\Rightarrow d=1$

Vậy $x-y, 4x+4y+1$ nguyên tố cùng nhau. Mà tích của chúng là scp $(x^2)$ nên bản thân mỗi số trên cũng là scp.

Đặt $4x+4y+1=t^2$ với $t$ tự nhiên.

Khi đó: $A=2xy+4(x+y)^3+x^2+y^2=(x+y)^2+4(x+y)^3=(x+y)^2[1+4(x+y)]$

$=(x+y)^2t^2=[t(x+y)]^2$ là scp

Ta có đpcm.

a) công có ích

`A_i = P*h = 10m*h=90*10*1,5=1350`

b) Lực kéo có ích

`F_i = A_i/l =1350/3=450(N)`

c) Công để thắng lực ma sát

`A_(hp) = F_(ms)*l=30*3 =90(J)`

a) Công có ích là:

���=�.ℎ=10�.ℎ=10.90.1,5=1350Aci​=P.h=10m.h=10.90.1,5=1350 (J)

b) Lực kéo trên mặt phẳng nghiêng khi không có ma sát là:

�=����=13505=270F=sAci​​=51350​=270 (N)

c) Công thắng lực ma sát là:

�ℎ�=���.�=30.5=150Ahp​=Fms​.s=30.5=150 (J)

Nhiệt năng của một vật là : tổng động năng của các phân tử cấu tạo nên vật . Nhiệt năng có quan hệ chặt chẽ đối với nhiệt độ : Nhiệt độ càng cao thì các phân tử chuyển động càng nhanh và nhiệt năng càng lớn .

Các cách làm thay đổi nhiệt năng của vật là :

- Thực hiên công

- Truyền nhiệt

Nhiệt năng của một vật là tổng động năng của các phân tử cấu tạo nên vật . 

Các cách làm thay đổi nhiệt năng của vật là :Thực hiên công,truyền nhiệt

a) Công suất dùng để xác định công thực hiện trong 1 đơn vị thời gian

b) Công suất của đầu lửa

`P= 1000*745,7=745700(W)`

ý nghĩ : trong vòng `1s` thì đầu xe lửa có thể thực hiện một công có độ lớn là `745700(J)`