Ko biết

\(\rarr\) I saw an elephant at the zoo yesterday. My brother wants to be an engineer in the future.

giải thích:

- Chúng ta dùng mạo từ "an" trước các danh từ bắt đầu bằng một nguyên âm (u, e, o, a, i). Cả "elephant" và "engineer" đều bắt đầu bằng chữ "e" nên chúng ta sử dụng "an".

Trả lời Câu 1: If you could invent a new school subject, what would it be and why?

Ý nghĩa tiếng Việt: Nếu bạn có thể phát minh ra một môn học mới, đó sẽ là môn gì và tại sao?

Ví dụ câu trả lời (bằng tiếng Anh và giải thích):

Answer: If I could invent a new school subject, it would be "Life Skills and Financial Literacy."

Why: I believe this subject is crucial because it teaches practical skills necessary for adult life that are often not covered adequately in the standard curriculum. Students would learn essential topics like budgeting, managing taxes, understanding basic contracts, cooking, and basic home maintenance. This knowledge is vital for becoming a responsible and independent adult.

Giải thích:

• Life Skills and Financial Literacy: Kỹ năng sống và Kiến thức tài chính.
• Crucial (adj): Quan trọng, thiết yếu.
• Practical skills: Các kỹ năng thực tế.
• Budgeting: Lập ngân sách.
• Independent adult: Người trưởng thành độc lập.

Trả lời Câu 2: What might happen if people depend too much on technology?

Ý nghĩa tiếng Việt: Điều gì có thể xảy ra nếu mọi người phụ thuộc quá nhiều vào công nghệ?

Ví dụ câu trả lời (bằng tiếng Anh và giải thích):

Answer: If people depend too much on technology, several negative things might happen. Firstly, critical thinking and problem-solving skills could decline because people rely on search engines or apps to find instant answers instead of thinking deeply. Secondly, there could be a loss of essential social skillsas face-to-face interactions decrease, leading to loneliness or misunderstanding. Finally, society becomes vulnerable to large-scale system failures (like power outages or cyberattacks) because we have lost the ability to function without digital tools.

Giải thích:

• Decline (v): Suy giảm.
• Critical thinking: Tư duy phản biện.
• Problem-solving skills: Kỹ năng giải quyết vấn đề.
• Face-to-face interactions: Tương tác trực tiếp mặt đối mặt.
• Vulnerable (adj): Dễ bị tổn thương.
• Cyberattacks: Các cuộc tấn công mạng.

One of my favorite fairy tales is Cinderella.

Cinderella was a kind and beautiful girl. After her father died, she had to live with her cruel stepmother and two stepsisters. They made her do all the housework every day. Although she was very sad, Cinderella always stayed gentle and hardworking.

One day, the king invited everyone to a royal ball. Cinderella wanted to go, but her stepmother did not allow her. Suddenly, her fairy godmother appeared and used magic to help her. She gave Cinderella a beautiful dress, glass slippers, and a carriage.

At the ball, the prince danced with Cinderella all night. Before midnight, Cinderella ran away and accidentally left one glass slipper behind. The prince searched the whole kingdom for the girl whose foot fit the slipper. Finally, he found Cinderella, and they got married and lived happily ever after.

Cinderella is a classic fairy tale about a kind and beautiful young woman who is cruelly treated by her wicked stepmother and two stepsisters. They force her to work as a servant in her own house.

One day, the Prince announces a grand ball. Cinderella is forbidden to go, but with the help of her Fairy Godmother, she is magically transformed and attends the ball in a beautiful gown and glass slippers. She is warned to return before midnight.

At the ball, Cinderella dances with the Prince and they instantly fall in love. As the clock strikes midnight, she rushes away, accidentally leaving behind one of her glass slippers.

The Prince vows to marry the woman whose foot fits the slipper. After searching the kingdom, he finally arrives at Cinderella's house. The stepsisters fail to fit the slipper. Finally, Cinderella tries it on, and it fits perfectly. She marries the Prince and lives happily ever after

Bn cứ học kĩ các từ vựng,công thức và làm đề nhiều là được(chắc thế)

bạn ơi chương trình phổ thông cơ bản nên chỉ cần chăm học từ vựng và cấu trúc là được mà

Câu 1

Gọi số cần tìm là: abc(tất cả những chỗ có abc hay cba bạn viết vào bài thì thêm cho mnihf một dấu gạch ngang ở trên nhé, mình không đnahs đc cái gach ngang)

Theo đề bài: a+b+c=12

Khi đảo ngược chữ số ta được số: cba

Số mới lớn hơn số cũ 198 đơn vị nên:

cba-abc=198

Ta có:

(100c+10b+a)-(100a+10b+c)=198

99c-99a=198

99(c-a)=198

c-a=2

Vì: a+b+c=12

Thay c=a+2:

a+b+a+2=12

2a+b=10

Chọn a=1 thì b=8, c=3.

Số cần tìm là 183

Vậy số cần tìm là 183.

Câu 2

Dãy số:

1, 4, 9, 16,25, ... là dãy các số chính phương:

1^2, 2^2, 3^2, 4^2, 5^2,...

Vậy 10 số đầu tiên là:

1^2+2^2+3^2+.....+10^2

Tổng 10 số đầu tiên:

1+4+9+16+25+36+49+64+81+100 =385

Vậy tổng 10 số đầu tiên của dãy là **385.

Can nay how Kho nha

Câu 1:

I don’t think robots can completely replace teachers. Robots can help students learn, but teachers can understand students and help them better. Teachers also make lessons more fun.

Câu 2:

Robots are better at dangerous and hard jobs. They can work in factories, clean dangerous places, and help doctors. Robots can work for a long time without getting tired.

Câu 1:

I don’t think robots can completely replace teachers. Robots can help students learn, but teachers can understand students and help them better. Teachers also make lessons more fun.

Câu 2:

Robots are better at dangerous and hard jobs. They can work in factories, clean dangerous places, and help doctors. Robots can work for a long time without getting tired.

Bài 28:

C = 4/3.5 + 4/5.7 + ... + 4/97.99

C = 2.(2/3.5 + 2/5.7 + ...+ 2/97.99)

C = 2.(1/3 - 1/5 + 1/5 - 1/7 + ... + 1/97 - 1/99)

C = 2.(1/3 - 1/99)

C = 2.32/99

C = 64/99

D = 18/2.5 + 18/5.8 + ... + 18/203.306

D = 6.(3/2.5 + 3/5.8 + ... + 3/203.206)

D = 6.(1/2 - 1/5 + 1/5 - 1/8 + ... + 1/203 - 1/206)

D = 6.(1/2 - 1/206)

D = 306/103

C/D = 64/99 : 306/103

C/D = 64/99.103/306

C/D = 3296/15147

Cho A = (196 + 197) / 198 ; B = (196 + 197) / (197 + 198). So sánh A và B

B = \(\frac{196+197}{197+198}\) = \(\frac{196}{197+198}+\) \(\frac{197}{197+198}\)

\(\frac{196}{197+198}\) < \(\frac{196}{198}\)

\(\frac{197}{197+198}\) < \(\frac{197}{198}\)

Cộng vế với vế ta có:

B = \(\frac{196}{197+198}+\) \(\frac{197}{197+198}\) < \(\frac{196}{198}+\frac{197}{198}\) = A

Vậy A > B

Bài 1:

1. most delicious
2. smartest
3. hottest
4. worst
5. most interesting
6. highest

Bài 2: 1 - B 2 - B 3 - B 4 - A

Bài 3:

1. Nam is the fastest in the team.
2. The red dress is the most expensive.
3. This is the most beautiful house I have ever seen.
   
   HI hi

1. This is the most delicious cake I have ever tasted.
2. Who is the smartest student in your group?
3. Yesterday was the hottest day of the summer.
4. It was the worst movie I've ever seen.
5. This is the most interesting book in the library.
6. Which is the highest mountain in the world?

1. Jupiter is the ________ planet in our solar system.
2. • Đáp án: B. largest
3. She is the ________ girl in the school.
4. • Đáp án: B. most beautiful
5. That was the ________ exam I've ever taken.
6. • Đáp án: B. most difficult
7. My brother is the ________ person I know.
8. • Đáp án: A. busiest

1. No one in the team is faster than Nam.
2. • \(\rightarrow \) Nam is the fastest person/player in the team.
3. This dress is \(\$50\). The blue one is \(\$70\). The red one is \(\$100\).
4. • \(\rightarrow \) The red dress is the most expensive (of the three).
5. I have never seen a more beautiful house than this one.
6. • \(\rightarrow \) This is the most beautiful house I have ever seen.

1. \(3n + 1 = x^2\) (1)
2. \(4n + 1 = y^2\) (2)

• Bước 1: Giới hạn giá trị của \(y\)
  Vì \(10 \le n \le 99\), ta có:
  \(4 \cdot 10 + 1 \le 4n + 1 \le 4 \cdot 99 + 1\)
  \(41 \le y^2 \le 397\)
  \(\Rightarrow 7 \le y \le 19\)
• Bước 2: Xét phương trình (2)
  Từ \(4n + 1 = y^2\), ta thấy \(y^{2}\) phải là số lẻ, nên \(y\) là số lẻ.
  Các giá trị \(y\) có thể là: \(\{7, 9, 11, 13, 15, 17, 19\}\).
• Bước 3: Thử chọn giá trị
  Ta lập bảng để kiểm tra điều kiện \(3n + 1\) là số chính phương:

Ta có:
\(x^2-x=x\left(x-1\right)\) với mọi x thuộc số nguyên dương
Khi đó
\(\left(a^2+b^2+c^2+d^2\right)-\left(a+b+c+d\right)=a\left(a-1\right)+b\left(b-1\right)+c\left(c-1\right)+d\left(d-1\right)\)
Và:
\(a\left(a-1\right)+b\left(b-1\right)+c\left(c-1\right)+d\left(d-1\right)\) chia hết 2
\(\Rightarrow\left(a^2+b^2+c^2+d^2\right)-\left(a+b+c+d\right)\) chia hết 2

Mà : \(a^2+b^2+c^2+d^2\) chia hết 2
\(\Rightarrow a+b+c+d\) chia hết 2
Với \(a+b+c+d\ge1+1+1+1=4\)
Vậy , a+b+c+d là hợp số

à mình quên thêm x(x-1) chia hết cho 2 nhé