Вопрос школьника по предмету Математика
Помогите решить систему уравнений с двумя неизвестными, даю 35 балов.
{x-y=3
{2x+y=6
Ответ учителя по предмету Математика
Ответ:
y=4 x=7
Пошаговое объяснение:
x-y=3
2x+y=6
Выражаем x из первого
x=3+y
2x+y=6
Подставляем во второй
2(3+y)+y=6
6+2y+y=6
3y=12
y=4
Подставим у в первое
x-4=3
x=4+3
x=7
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English is the most spoken language in the world that is why it is very important to speak and understand it.
All business is in English.
A lot of world’s mail and telephone calls
Everybody knows that ability to speak a foreign language is very important in today’s world I personally believe that the most useful foreign language today is English.
First of all. English is the most popular language in the world. It is spoken about 470 million people throughout the world, and geographically it is the most widespread language on Earth. It is used in business and trade: a lot of the world’s mail and telephone calls are in English.
Secondly. English is very useful for traveling. It is the official language of about 45 nations, and in the countries where English is not the official language, a lot of people speak h anyway. For example, in France, Germany or Italy you can find many people who are able to speak English. If you don’t know the languages of these countries, you can use English for communication.
English is very important for culture and education. A lot of articles, films, books and radio programmers’ are in English. Not all of them are translated into Russian. So if you want to know what they are about, you should learn English.
In the conclusion I want to say, that I believe that learning English is very useful for me and everybody else. I have been studying it for 8 years and I am going to improve it further.
(Смешанные дроби)