Предмет: Алгебра, автор: bmolko

системы уравнения способ сложения

5x+y=30  
3x-4y=41  

Ответы

Автор ответа: Катерина0000
0

{5x+y=30 *4    {20х+4у=120      23х=161   х=7   5*7+у=30   у=-5   ответ (7;-5)

  3x-4y=41          3х-4у=41

Предыдущий вопрос
Следующий вопрос
Похожие вопросы
Предмет: Английский язык, автор: Konstantin19962018
Составьте по 3 вопроса каждого типа, основываясь на информации из текста.


America`s Oil


During the summer of 2000, lots of car-drivers in America were angry: the cost of gasoline went above $2 a gallon in some states. Which meant the end of the age of cheap gasoline.

Today, in 2020, in spite of Covid-19, gas costs over $ 2 a gallon almost everywhere in the USA, while in California, even regular gas costs above $3 a gallon. This is very cheap compared to Europe, but Americans think that it is very expensive.

The United States is the land of relatively cheap energy; America is the second biggest producer of oil in the world, but it is also the biggest importer. In fact, the USA imports over 20% of its energy, mostly in the form of oil.

There is oil under the ground in many parts of the USA. America's first oil wells were drilled in the year 1859, in Pennsylvania; and since then, more and more wells have been made and rigs have been erected in other states.

Today, oil companies are "fracking", and finding lots more oil under the ground. The center of America's oil industry today is the state of Texas; and America's "oil capital" is the city of Dallas. Texas is by far the biggest producer of oil in the USA.

It was not always the case; the first Texan oil-wells were opened in 1901, when there was already a big oil industry in other parts of the USA. But without the oil from Texas, America's history would have been very different.

In 2001, Texans celebrated their "oil centenary".

Cheap oil and cheap gasoline helped to make modern America: they shaped America's cities, and they were an essential part of the American lifestyle. They were also essential in the great empty states of the West, where people often have to travel long distances.

Today, Americans consume about 25% of the world's energy.... far more than people in other countries; but the situation is slowly changing.

Americans are already buying smaller cars, and American cars consume much less gas than they used to. But in the coming years, they will use less and less oil – they will have to.

There is still a lot of oil under the ground, but oil and gas must become more expensive in the future. Over 50% of America's traditional oil reserves have already been depleted – mostly since 1950. Nobody knows when America's oil will start running out, but the first shortages could come in less than 20 years. And as soon as oil starts running out, its price will go up very quickly!​
7 лет назад
Предмет: Русский язык, автор: Irisha5101
Стилистическая окраска слова звезда -?( нейтральное, разговорное, просторечное, книжное, высокое)
и сфера употребления этого слова -?( общеупотребительное, диалектное, профессиональное, жаргонное) СРОЧНО!!!
7 лет назад
Предмет: Химия, автор: zka15381
При восстановлении железа из оксида железа (III) алюминием образовалось железо массой 224 г. При этом количество вещества алюминия, вступившего в реакцию, составило
7 лет назад
Предмет: Математика, автор: лиличкацветочек
помогите решить такие деления в столбик: 623:7 378:9 475:5.
10 лет назад
Предмет: Литература, автор: murkaaa

Какие произведения есть о русском языке??
10 лет назад