please help me i really need it i know that it is a lot but i could really use it

1. 1/49
2. 1/625
3. 1/8
4. 1/216
5. 1/64
6. 25/121?
7. 1/256
8. -1/531441?
9. a^4/9
10. 1/12t^3
11. 25/b^4
12. 7/r^7
13. 4x^5/y^3
14. 3g^3
I hope this is all right, if it's not I apologize.