Chứng tỏ A chia hết cho 6 với A = 2 + 2² + 2³ + 2⁴ + … + 2¹⁰⁰

Ex -3. Em hãy viết lại những câu sau sao cho nghĩa không đổi.

1. He is twelve years old. => He is at……………………….…………..

2. Lam is fifteen years old. => Lam is…………………………..…fifteen.

3. My father is forty years old. => My father is………………..……………

4. Mr. Tuan is at the age of sixty. => Mr. Tuan is……………….…………….old

5. My mother is thirty-five. => My mother………………….……………

6. Nam is twelve years old. => Nam is…………………….……………..

7. Mr. Tuan is at the age of 45. => Mr. Tuan……………………..…………..

8. Miss Nga is at the age of nineteen. => Miss Nga……………………………

9. Trung is at the age of fourteen. => Trung is………………………..…………

10. Nam and Ba are eleven years old. => Nam and Ba………………….……