1. We went skiing yesterday

2. Did you watch the men's basketball final on Tv last night?

3. I did not play badminton last Saturday because I was ill

4. Sue and her friends is doing yoga in the gym now

5. Last week we studied how to surf. It was very interesting

6. He usually plays football with his friends on Saturdays

7. Where the children were yesterday morning? They were at the swimming pool.

8. His father taught him how to play football when he was a very young age

15. B

16. B 

17. C

18. A

19. B

Ex9:

1. We didn't win match last week because some good players didn't join

2. How do you go to the gym?

3. What is your favourite football team?

4. Don't watch TV too much

5. Did Mai play badminton with you yesterday?

Ex 10:

1. mình chưa làm đc xl bn nha

2.What is your favourite Tv programmares?

3. mình chưa nghĩ đc xl bn

4. I have a lot of outdoors so I have no time to watch

4. Were they not 

5. was not

6. Was

7. Was

8. Were

9. Were

10. Was

11. was

12. was

13. were

14. was

15. was

B.

1. wore

2. did you do

3. taught

4. Did-watch

5. did you go

6. Did - stay

7. did

8. did you leave

9. did you finish

10. did you go

11. thought

12. watched

13. wore

14. did not stop

15. Did you listen

cho mình đúng ddc ko ạ

1. saw - did not like

2. Did Marco win

3. did not play

4. did

5. was - went

6. Did you go

7. Did you call

8. came

9. had

10. did not to drink

11. did not to be

Ta có: \(\dfrac{4}{5}=\dfrac{72}{90}\);\(\dfrac{8}{15}=\dfrac{48}{90}\);\(\dfrac{-3}{2}=\dfrac{-135}{90}\);\(\dfrac{-2}{10}=\dfrac{-18}{90}\);\(\dfrac{-7}{9}=\dfrac{-70}{90}\)

\(e.\dfrac{7}{10}\cdot\dfrac{-3}{5}+\dfrac{7}{10}\cdot\dfrac{-2}{5}-\dfrac{3}{10}\)

\(=\dfrac{7}{10}\cdot\left[\left(\dfrac{-3}{5}\right)+\left(\dfrac{-2}{5}\right)\right]-\dfrac{3}{10}\)

\(=\dfrac{7}{10}\cdot1-\dfrac{3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)

\(f.\dfrac{-3}{7}\cdot\dfrac{5}{9}+\dfrac{4}{9}\cdot\dfrac{-3}{7}+2\dfrac{3}{7}\)

\(=\dfrac{-3}{7}\cdot\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{17}{3}\)

\(=\dfrac{-3}{7}\cdot1+\dfrac{17}{3}=\dfrac{-9}{21}+\dfrac{119}{21}=\dfrac{110}{21}\)

\(g.\dfrac{5}{9}\cdot\dfrac{10}{17}+\dfrac{5}{9}\cdot\dfrac{9}{17}-\dfrac{5}{9}\cdot\dfrac{2}{17}\)

\(=\dfrac{5}{9}\cdot\left(\dfrac{10}{17}+\dfrac{9}{17}-\dfrac{2}{17}\right)\)

\(=\dfrac{5}{9}\cdot1=\dfrac{5}{9}\)

16.C

17.B

lời giải thích: