Độ dài của đáy bé là:

        \(150\times\dfrac{3}{5}=90\) ( \(m \) )

Chiều cao của mảnh đất hình thang là:

      \(\left(150+90\right)\div2=120\) ( \(m \) )

Diện tích của mảnh đất đó là:

        \(\dfrac{150+90}{2}\times120=14 400\) ( \(m^2\) )

               Đáp số: \(14400m^2\)

a)

Số học sinh đi Đầm Long là:

\(45 .\dfrac{1}{3}=15\) ( học sinh )

Số học sinh đi Khoang Xanh là:

\(\left(45-15\right)\dfrac{2}{3}=20\) ( học sinh )

Số học sinh đi Đảo Ngọc Xanh là:

\(45-\left(15+20\right)=10\) ( học sinh )

b)

Tỉ số phần trăm của số học sinh chọn đi Đảo Ngọc Xanh so với học sinh cả lớp là:

\(10:45=22,22\%\)

1. My brother hasn't play any sport since last year.

2. We had known her since she arrived in our city.

3. Kathy has wanted to go to Queensland for a long time.

4. She has bought that bike for 4 months.

5. I have slept for a long time.

6.They had moved to London since I was a little girl.

7. She hasn't played the piano for 2 months.

8. This is the first time we have been to Da Nang.

9. I have read this story for 2 times.

10. They haven't eaten breakfast yet.

11. I have never met him before.

12. The last time I met my dad was 2 months ago. Have you ever been in New York?

13. This is the best film I have ever watched.

14. Last week, I made a very big mistake.

II. Bị động với động từ khuyết thiếu

1. Nam can fix the bike well.

→The bike can be fixed well by Nam.

2. She is going to read a new novel tomorrow.

→A new novel is going to be read by her tomorrow.

3. You must do your homework regularly.

→Your homework must be done regularly.

4. He used to write poems when he was young.

→Poems used to be written when he was young.

5. John ought to wash his clothes every day.

→His clothes ought to be washed everyday.

6. They are going to plant trees along the sidewalk.

→Trees are going to be plant along the sidewalk.

7. No student can solve this problem.

→This problem can't be solved by any student

tui

bạn còn chưa trả lời câu 22,23,24&25