Добавить задачу

Решение задачи #76095

(21/47:26/47)*13/27-(20*1/26)*13/27

(21/47:26/47)*13/27 - (20*1/26)*13/27 = (21/26)*(13/27) - (20/26)*(13/27) = (1/26)*(13/27) = 1/54