Subtracting Fractions

Question 1:

6 7 - 4 7
2 7

Question 2:

3 5 - 1 5
2 5

Question 3:

2 3 - 1 3
1 3

Question 4:

8 15 - 2 6
6 30 = 1 5

Question 5:

11 15 - 4 6
2 30 = 1 15

Question 6:

5 6 - 11 15
3 30 = 1 10