Выполнить5/8×5/6-1/4×5/6
5/8 * 5/6 - 1/4 * 5/6 = 5/6*(5/8 - 1/4) = 5/6 *(5/8 - 2/8) = = 5/6 * 3/8 = 15/48 = 5/16