Предмет: Математика, автор: думающий

10 слив имеют такую же массу, как 3 яблока и 1 груша, а 2 сливы и 1 яблоко - как 1 груша. Сколько нужно взять слив, чтобы их масса была равна массе 1 груши?

Ответы

Автор ответа: Влад1995308
0

Обозначаем массу сливы за x, массу яблок - за y, а груш - за z.
Тогда мы имеем систему из двух уравнений:
3y+z=10x
2x+y=z

10x-3y=z
2x+y=z
Отсюда следует, что 2x+y=10x-3y
Переносим всё влево и приводим подобные:
-8x=-4y
2x=y
Берём уравнение 3y+z=10x и подставляем вместо y 2x:
3*2x+z=10x
6x+z=10x
z=10x-6x
z=4x
Выходит, масса одной груши равна массе четырёх слив. То есть, ответ: 4.

Похожие вопросы
Предмет: Информатика, автор: kozonalievazibek
Предмет: Английский язык, автор: taisia81
Переводите пожалуйста тексты. A gift or a curse?
D
1
They had difficulties learning to read and to
write. Their classmates laughed at them, their
teachers often thought they were stupid and lazy,
their parents despaired. Most of them hated to go
to school and wanted to drop out of school as
soon as possible. In short, they had unhappy
school years.
2
Some of the world's greatest composers,
writers and inventors had an unpleasant time at
school like this. Later, when they became
successful, nobody was more surprised than their
old classmates. Were these people stupid? No, of
course not.
3
Dyslexia is a lifelong challenge that people are
born with. It means that people have problems
with reading, writing, spelling and sometimes with
memorising things. Dyslexia is not a sign of poor
intelligence or laziness. Nor is it the result of poor
instruction. Children and adults with dyslexia
simply process and interpret information
differently. Dyslexia occurs among people of all
economic and ethnic backgrounds. Often more
than one member of a family has it. Statistically,
about 15 percent of people are dyslexic, but not all
of them realise it.
4
Some experts think, however, that dyslexic
people are highly creative and intuitive because
their brain works differently. A good example is
Vladimir Mayakovsky, a renowned Russian and
Soviet poet, who had trouble with commas and
full stops but created his own revolution in
poetry. He changed the very idea of poetry by
introducing new subjects, new vocabulary and
new rhythms.
5
Some people with dyslexia discover they have
special, hidden talents, but only when they are
older. A good example is Agatha Christie, one of
the most successful writers in history – two billion
books published in 44 languages! At school she had
problems with writing and often got bad marks for
essays. Her parents were disappointed and wanted
Agatha to leave school early. She only started
writing because her older sister said she couldn't
do it! And even when she was already a famous
crime writer, she sometimes felt embarrassed
because she still couldn't spell.
6
There is a long list of people like Vladimir
Mayakovsky and Agatha Christie, writers and poets,
inventors and artists, actors and politicians. Hans
Christian Andersen, Albert Einstein, Leonardo da
Vinci, Pablo Picasso, Tom Cruise, Keanu Reeves -
to name just a few. These important and creative
people had problems with reading and writing
when they were young. Of course, that doesn't
mean that if you have dyslexia, you will become
a genius in time, but it shows that dyslexia may be
a gift and not a curse,​