ПОМОГИТЕ РЕШИТЬ ПОЖАЛУЙСТА!!!

 

В серной кислоте при нагревании полностью растворился оксид  меди 2, масса которого 4г. Какое количество вещества соли оброзовалось  при этом

Решите пожалуйста 

х4-4х3+8х2-8х+4=0

Назовите причины увелечения отрыва экономики СССР от экономики западных стран 70-х- начале 80-х гг.

Доклад . тема.Урал. Драгоценные и поделочные камни,золото,алмазы.

Вставьте глагол to be в Present Simple.

1. I ... a pupil. 2. My father ... not a teacher, he ... a scientist. 3. ... your aunt a doctar? - Yes. she ... . 4. ... they at home? - - No, they ... not at home, they ... at work. 5. My brother ... a worker. He ... at work. 6. ... you an engineer? - - Yes, I ... . 9. ... tour sister at school? - No, she ... not at school. 10. My ... sister ... at home. 11. ... this your watch? - Yes, it ... . 12.She ... an actress. 13. This ... my bag. 14. My uncle ... an office-worker. 15. He ... at work. 16. Helen ... a painter. She has some fine pictures. They ... on the walls. She has much paper. It ... on the shelf. The shelf ... brown. It ... on the wall. Helen has a brother. He ... a student. He has a family. His family ... not in St. Petersburg, it ... in Moscow.