Factor each of the following completely or state if the polynomial is not factorable

1. a⁴-b⁶
2. c²-81
3. 4h²-49
4. 16j²-81k²
5. 1-25q⁴
6. 16r⁴-121
7. 5t³-20t
8. 72v-8v³
9. 0.01e²-f²g²
10. 144h²-49i²
11. (j+k)²-400
12. 18L²-2(m+3n)²
13. 16(q+2q)²-25r²
14. 1/36-1/9x²
15. 1/4c²+1/100d²​