Номер 1
1 4/9 * 1 5/13 - 2 1/12 * 4/15 = 13/9 * 18/13 - 25/12 * 4/15 = 2 - 5/9 = 1 4/9.
Номер 2
2 2/7 * 2 5/6 - 1 3/4 * 2/7 + 2 2/7 * 2/3 = 16/7 * 17/6 - 7/4 * 2/7 + 16/7 * 2/3 = 136/21 - 1/2 + 32/21 = 136/21 + 32/21 - 1/2 = 168/21 -1/2 = 8 - 1/2 = 7 1/2.