22. It's waste of time to try and explain anything to Henry

→ It's not worth the time to try and explain anything to Henry.

23. She didn't like to learn her lessons in the evening

→ They made her  learn her lessons in the evening.

24. Why did you read this book ? It wasn't useful

→ It's wasn't useful.

25. Could you please turn off the TV ?

→ Would you mind turning off the TV?

C

c

C. 24 chữ cái.

20,23*20,24-20,22*8,25-20,22*5,9-2,022*60,9

=20,23*20,24-20,22(8,25+5,9+6,09)

=20,23*20,24-20,22*20,24

=20,24*(-0,01)

=-0,2024

20A 21C 22B

Bạn chụp mặt trước nữa thì mình mới giúp được hết nha

B - A - D - C - C

đề phòng hình bị lỗi

21, phones

22, invent

Câu 22:  invent

22. are invented

22B

\(P=\left(sin^2x-1\right)tan^2x+\left(cos^2x-1\right)cot^2x\)

\(=-cos^2x.\dfrac{sin^2x}{cos^2x}+\left(-sin^2x\right)\dfrac{cos^2x}{sin^2x}\)

\(=-sin^2x-cos^2x\)

\(=-\left(sin^2x+cos^2x\right)\)

\(=-1\)