rút gọn biểu thức sau:

( 3u^2 + 2v ) ( u - 2v )

Each sentences has a mistake. Find and correct it:

1. Children are hooked in playing games. → .......................

2. Use computers too much has harmful effects on both their minds and bodies. → .......................

3. Both the students and the teacher has to do sports every day. → .................

4. Doing exercises every day make all of us good. → .............................

5. The future will presure children under studying well. → .........................

6. Have you ever risked to go abroad alone ? → ......................

7. When i left home last Sunday, the sun shone. → ......................

8. As soon as the boy left for Ha Noi, he was causing an accident. → ..............

9. We must be responsible to the authority about polluting the environment. →..........................

10. What percent of students passed the exams last year ? → .....................

11. Among the famous students has his oldest son. → .......................

a. It's time for us to spend more time on doing research.

→ We ...................................................................

→ It's time we .......................................................

b. It is such a deep river that children can't swim alone.

→ The river ...........................................................

c. He is the most generous teacher i have ever met.

→ I have never ......................................................

d. We pride ourselves on our children's progress.

→ We are ..............................................................

e. Students should pay more attention to what the teacher says.

→ It's time ..............................................................

f. Nobody has ever solved that problem.

→ That problem ......................................................

→ 

C/m rằng:

a/ 2 + 2^2 + 2^3 + 2^4 + 2^5 + 2^6 chia hết cho 3

b/ 2 + 2^2 + 2^3 + ..... + 2^6 chia hết cho 7

c/ 3 + 3^2 + 3^3 + ..... + 3^120 chia hết cho 40

d/ n^2022 + n^2023 + n^2024 chia hết cho n^2 + n + 1

Phân tích đa thức thành nhân tử:

x^4 + 4

phân tích đa thức thành nhân tử:

8x^2 + 10x - 3

phân tích đa thức thành nhân tử:

3x^2 + 14x + 8

Phân tích đa thức thành nhân tử:

3x^2 + 8x + 5