Ответ Автор - svetazuna 13.1)(2 13/17 - 1 11/17) + 12/17 = 1 2/17 + 12/17 = 1 14/17,2)4 5/13 + 1 6/13 - 3 8/13 = (4 + 1 - 3) + (5/13 + 6/13 - 8/13) = = 2 + 3/13 = 2 3/13,3)5 9/11 - 3 5/11 + 2 3/11 = (5 - 3 + 2) + (9/11 - 5/11 + 3/11) = = 4 + 7/11 = 4 7/11