№1.
1) 2 5/18 - 5 1/12 = 2 10/36 - 5 3/36 = -(5 3/36 - 2 10/36) = - (4 39/36 - 2 10/36) = - 2 29/36
2) - 2 29/36 + 1 2/9 = -2 29/36 + 1 8/36 = -(2 29/36 - 1 8/36) = -1 21/36 = - 1 7/12
3) 3,8 * (- 7/12) = 38/10 * (-7/12) = - 133/60 = -2 13/60
4) 1,2 + (-2 13/60) = - (2 13/60 - 1 2/10 = - (2 13/60 - 1 12/60) = - 1 1/60
№2.
-4 1/18 - 1 1/5 = - 1 5/90 - 1 18/90 = - (1 5/90 + 1 18/90) = - 2 23/90
2) - 2 23/90 + 3 8/15 = - 2 23/90 + 3 48/90 = 3 48/90 - 2 23/90 = 1 25/90 = 1 5/18
3) 1 5/18 * 3,6 = 23/18 * 36/10 = 23/5 = 4,6
4) 4,6-2,6=2