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
4. Choose the correct words in italics.
Good morning everybody and welcome. All of you have chosen to join the international division. So that means that 1 you're going to start a new job in one of our regional offices. At 10 o'clock, Delores Tavares 2 is coming to talk to you about culture. But first 3 I'm going to explain a few points to help you prepare for the move to a new country. Please stop me if you 4 have any questions. First, some practical points. You 5 must make sure that your passport is up-to-date. And if you need to apply for a visa, 6 do it as soon as possible. It can take a lot of time, so 7 you mustn't leave it till the last minute. The admitistrative staff will help you. Some of you 8 are travelling with your families so you'll 9 should check the travel documents for your family.
How each of you 10 is going to have a one-week trip to your new location before you start the job. This trip 11 will give you the chance to find out about the new environment. You 12 should make the best use of this trip. We want you to start your new job without too many problems. As you know you 13 don't have to look for accommodation because the company is going to provide you with an apartment. But 14 don't expect everything to be easy. The way of life in other countries is often very different. You 15 shouldn't forget that!
5. Choose the correct option a-c to complete the text.
Buenos Aires is a leading business 1 a location. It has a 2 b strong
economy. International trade plays a key role in the 3 b development of the city. The country exports many products through its historic 4 c port. Many international banks
have their 5 a regional offices here.
1 a location
a large
3 a growing
4 a airport
5 a regional
b site
b strong
b development
b pitch
b capital
c placement
c fat
c increase
c port
c investment
Do you like travelling?
Have you ever been abroad? Did you go abroad for your summer holiday?
How many cities have you visited? How many cities did you visit last summer?
Are you airsick? Did you get airsick on your last flight?
What means of transportation do you prefer? Do you like travelling by sea/by air/by land?