Subtracting Mixed Numbers

Question 1:

4 3 5 - 3 1 9
67 45 = 1 22 45

Question 2:

3 1 2 - 1 3 4
7 4 = 1 3 4

Question 3:

5 4 5 - 1 1 2
43 10 = 4 3 10

Question 4:

4 1 2 - 2 1 10
24 10 = 2 4 10 = 2 2 5