Один маляр берётся выполнить работу за 8 дней, а другой – за 6 дней. Работая один после другого, они выполнили работу за 7 дней. Сколько дней работал каждый?

как решить систему 2x-3y+z-10=0. 3x-4y-z+2=0. x+y+z=0. только напишите пожалуйста подробною а то я вообще не поняла как решатью спасибо

Из данных английских грамматических форм выберите ту, которую Вы употребили бы при переводе следующих  предложений

1.I wonder why she (be) so selfish. She isn't usually like that.
has been
is
is being
would be

2. We (see) Rose two days ago.
had seen
have seen
saw
were seeing

3. This time last year I (live) in Turkey.
had been living
had lived
lived
was living

4. Would you like something to eat? No, thank you. I just (have) breakfast.
had
had had
have been having
have had

5. It's the second time he (drive) a car.
drives
has been driving
has driven
is driving

6. Jill (write) three letters today.
had written
has written
was writing
wrote

7. It's three years since I last (see) my uncle.
had seen
has seen
saw
would have seen

8. I did Spanish at school but I (forget) most of it.
forgot
had forgotten
have forgotten
should forget

9. Chris (leave) school in 1997.
had left
has left
left
would have left

10. The man I (see) yesterday told me he never used a computer.
had seen
has seen
saw
would see

Масса дыни 8 кг. Сколько кг в 1/2 дыни?

Упростите выражение 2m-4m^2/m+1 * m+1/2m^2 и найдите его значение при m=1/4

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