ставлю 5 звезд Поставьте вместо пропусков глагол play, go или do. 1. Does she ………………………. dancing twice a week? (do / play / go) 2. It is dangerous to ……………………. skating on this lake. (do / play / go) 3. Mary likes to ……………………… a good game of draughts. (do / go / play) 4. We ………………………… swimming in the river. (go / do / play) 5. He ……………………….. aerobics now. (go / do / play) 6. John …………………….. tennis at the national level. (play / do / go) 7. Our family always …………………………. hiking in summer. (play / do / go) 8. His children ………………………. football for a local club. (play / go / do) 9. She …………………….. sailing every week. (play / go / do) 10. Peter and Jack …………………….. boxing. (play / go / do)

1. I ..have...already this film (seen). 2. My brother...has..already this news (heard). 3. Wehave already lunch ( had). 4. My friends haveto this artist recently (spoken). 5.I ..have never ... to Paris ( been). 6. My sister has this dress since my wedding (not worn) 7. Wefood yet (have not bought). 8. My brother asleep yet (has not  fallen).  9. I ... cold for a long time (have not caught). 10. Have you your certificate? (found) 11. Has your friend his word? (to kept) 12. Have you ever ... to London? (been) 13. What have you ? ( lost) 14. Where have you ? (been) 15. What have you ? (chosen) 16. Who has ? (to left) 17. Who has you such advice? ( given) 18. My colleaguehis car by the end of the month (has sold). 19. My uncle his new book of poetry by the beginning of the year (will  have  finished). 20. Unfortunately, our manager forgot what he... tons, (had promised) 21. My sister knew that my friendme on the phone so far ( had not reached). 22. Our friends by next summer (hd married) 23. We this matter by next Monday (wiil  have  thought over). 24. These peopleon our conditions by the evening (will have  agreed). 25. No doubt, our parents. us by tomorrow (will  have  forgive).

Пошаговое объяснение:

Обозначим красные воздушные шары - "К", зелёные - "З", синие - "С".

Пусть в коробке лежит х "К". ⇒ "З"=х/8 , а "С"≥1.

x+\frac{x}{8}+C=19.\ \ \ \ \ \ \ \ (1)x+

8

x

+C=19. (1)

Количество воздушных шаров - целое число. ⇒

\frac{x}{8}

8

x

- должно быть целым числом. Исходя из условия задачи х может равняться 8 и 16.

Подставляем х=8 в уравнение (1).

\begin{gathered}8+\frac{8}{8}+C=19\\8+1+C= 19\\9+C=19\\C=10.\end{gathered}

8+

8

8

+C=19

8+1+C=19

9+C=19

C=10.

Но по условию задачи "К">"C"≥1 ⇒ х≠8.

Подставляем х=16 в уравнение (1).

\begin{gathered}16+\frac{16}{8} +C=19\\16+2+C=19\\18+C=19\\C=1.\end{gathered}

16+

8

16

+C=19

16+2+C=19

18+C=19

C=1.

По условию задачи "К">"C"≥1 ⇒ x=16