дано аn...вычислите СУММУ 15 членов,если а6=18,d=2

Решите пожалуйста, последнее осталось. Все решил, а до этого не додуматься =\

Comlete the text with the prepositions from, for, of, with or to if necessary My dream has come true. I have never been ...Great Britain before. I stayed ... in England ...five days. I stayed ... my friend`s family. They live not far ...London. Of course I went ... London every day. London is full ... places of interest. They city is famous ... its historical museums, royal palaces and monuments. I took a lot ... photos. Would you like to see them some time? Come ... my house and we can look at them. The photos are worth seeing.

напишите отзыв к стихотворению, не с интеренета, пжлст, стихотворение любое

Чему равен магнитный поток в том случае когда плоскость контура расположена вдоль линий магнитной индукции?