из сетки с мячами взяли 4 мяча и в ней ещё осталось 12 мячей на сколько мячей больше осталось чем взяли

Сделать из этого текста пересказ пжалуйста мне очень надо на завтра:

In Great Britain school begins at the age of five. Many boys and girls usully leave school at the age of 16-en.

  In England the school year begins in September? but not always on the first day of the month, as school never begins on Monday.The English think that Monday is not a good day to start school. So pupils usually begin their school year on the first Tuesday of September (not always on the 1st of September as we do). The weather is usually fine. It is warm. The sky is often blue and the sun is bright. Little children going to school with their parents on their first school day look so clean and nice. They dont have any bags or books with them, as there is no need for these things on their first day at school.

а)5х+8х при х=13

б)39х-5х-4х+28 при х=3; х=5

Очень нужно даю 32 пункта 

Равновесие в системе : 2NO + O2 --> <-- 2NO2 установилось при следующих концентрациях:
1) [NO] = 0?12 моль/л

2) [NO2] = 0,24 моль/л
Определите константу равновесия.
Укажите условия для смещения равновесия вправо.

как перевести 9 в степени 2.25 в 3 со степенью 4.5 ????