20 - 18,6: (6 11/15 - 4 3/20) = 12,8
6 11/15 - 4 3/20 = 6 44/60 - 4 9/60 = 2 35/60 = 2 7/12
18,6:2 7/12 = 18,6 : 31/12 = 18,6*12/31 = 0,6*12= 7,2
20 - 7,2 = 12,8
1/6X - 0,82 = 3/8X - 1,37
- 0,82 + 1,37 = 3/8X - 1/6X
0,55 = 18/48X - 6/48X
0,55 = 10/48X
0,55 = 5/24X
X = 0,55:5/24 = 0,55*24/5 = 2,64