13. Do you think the police should speak to I ?

14. Can you play the violin?

15. They can’t draw well

16. She can’t sleep

17 I don't think Anita should accept this job

18. Are you sure we should do it?

19. Can you cook ?

20. Can I watch television?

1. Don't let him use my umbrella! 

2. Take the first turning on the right! 

3. Don't tell me such things.

4. Don't speak like that. 

5. Don't pay attention to her. 

6. Don't drive too fast. 

7. Close the door. 

8. Sit down and open your book page 26.

9. Jeff shouldn't work so much.

10. We should take our umbrellas.

11. I can play basketball.

12. Can we come to your house?

13. Do you think the police should speak to I 

14. Can you play the violin?

15. They can’t draw well.

16. She can’t sleep.

17 I don't think Anita should accept this job.

18 Are you sure we should do it?

20. Can I watch television?

A(x)+B(x)= x^3 + 2x^2 -x+1+2x^3 +3x^2 +4x +5

= ( x^3 +2x^3) + ( 2x^2 + 3x^2) + ( -x +4x ) + ( 1 +5) 

= 3x^3 + 5x^2 + 3x +6

A(x) - B(x) = x^3 +2x^2 -x+1 - 2x^3 - 3x^2 -4x-5

= (x^3 - 2x^3) + ( 2x^2 - 3x^2) + ( -x -4x ) + ( 1-5)

= -x^3 - x^2 - 5x-4

 Đây nha bạn :)