Subtracting Fractions

Question 1:

2 3 - 1 3
1 3

Question 2:

3 4 - 2 4
1 4

Question 3:

4 5 - 3 5
1 5

Question 4:

3 5 - 2 4
2 20 = 1 10

Question 5:

8 10 - 1 8
27 40

Question 6:

7 8 - 1 12
19 24