Subtracting Mixed Numbers

Question 1:

2 4 9 - 2 1 3
1 9

Question 2:

3 2 3 - 2 1 5
22 15 = 1 7 15

Question 3:

5 5 6 - 3 4 9
43 18 = 2 7 18

Question 4:

1 1 2 - 1 2 7
3 14