fraction questions

1. 3/9+7/9=1

2. 4/12+1/12=

3. 15/7=1/7

4. 7/20+13/20=

5. 0.3+6= 6.3

6. 9/12+12/12= 13/4

7. 3/17+16/17= 19/17

8. 3/4+11/4=2

9. 1/4+3/4=1

10. 3/8+15/8=2

11. 17/3= 52/3

12. 25/6= 41/6

13. 7/12+9/12=14/12

14. 9/3+4/3=4

15. 12/5+3/5=3