1и 2 с подробным ответом. пролежала месяц в больнице с сотрясом и сейчас вообще ничего не понимаю

Разложим числа в числителе и знаменателе на простые числа Числитель: 2 * 9 * 12 = 2 * 3 * 3 * 2 * 6 = 2 * 3 * 3 * 2 * 2 * 3.
Знаменатель: 6 * 8 * 3 = 2 * 3 * 2 * 4 * 3 = 2 * 3 * 2 * 2 * 2 * 3.
То есть получим следующее выражение:
(2 * 9 * 12) / (6 * 8 * 3) = (2 * 3 * 3 * 2 * 2 * 3) / (2 * 3 * 2 * 2 * 2 * 3).
Произведем сокращение одинаковых чисел в числителе и знаменателе. (2 * 3 * 3 * 2 * 2) - эта скобка общие сокращаемые числа.
Числитель: (2 * 3 * 3 * 2 * 2 * 3) / (2 * 3 * 3 * 2 * 2) = 3.
Знаменатель: (2 * 3 * 2 * 2 * 2 * 3) / (2 * 3 * 3 * 2 * 2) = 2.
Следовательно, выражение (2 * 9 * 12) / (6 * 8 * 3) после сокращений станет равным 3/2.
6 * 25 / 35 * 8 = (3 * 2 * 5 * 5) / (5 * 7 * 2 * 2 * 2) = (3 * 5) / (7 * 2 * 2) = 15/28.
9 * 5 + 9 * 3 / 2 * 81 = 9 * 5 + (3 * 3 * 3) / (2 * 3 * 3 * 3 * 3) = 9 * 5 + 1/6 = 45 + 1/6 = 270/6 + 1/6 = 271/6.
ответ: (2 * 9 * 12) / (6 * 8 * 3) = 3/2; 6 * 25 / 35 * 8 = 15/28; 9 * 5 + 9 * 3 / 2 * 81 = 271/6.

5*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*55*5 5*5.