Пошаговое объяснение:
1) = 23/24 - 21/24 = 2/24 = 1/12
2) = 1/1 * 2/4 = 2/4 = 1/2
3) = 91/14 : 17/6 =
91/14 * 6/17 =
91/7 * 3/17 = 273/119 = 2. 35/119 = 2. 5/17
