2. a) 13 2/3 - 6 3/7 : 1,2

13 2/3 - 6 3/7 : 1,2 = 13 2/3 - 45/7 : 12/10 = 13 2/3 - 45/7 : 6/5 = 13 2/3 - 45/7 * 5/6 = 13 2/3 - (45/6) * (5/7) = 13 2/3 - 15/2 * 5/7 = 13 2/3 - 75/14 = 13 2/3 - 5 5/14 = 13 28/42 - 5 15/42 = 8 13/42