1.
1) 5/6-1/3 = 5/6-2/6 = 3/6 = 1/2
2) 1/3-5/6 = 2/6-5/6 = -3/6 = -1/2
3) 1/2:(-1/2) = -1
2.
1) 1/2-2/3 = 3/6-4/6 = -1/6
2) 2/3-1/2 = 4/6-3/6 = 1/6
3) (-1/6):1/6 = -1
3.
1) 1/3-1/7 = 7/21-3/21 = 4/21
2) 3/7-1/3 = 9/21-7/21 = 2/21
3) 4/21:2/21 = 4/21*21/2 = 2
4.
1) 5/6-5/8 = 20/24-15/24 = 5/24
2) 1/8-1/3 = 3/24-8/24 = -5/24
3) 5/24:(-5/24) = -1