Hi everyone! I have about 200 problems on factoring, all due tmrw! I'm really stuck on a few of these, and if you could help me that would be great!

12m^3 y - 75my^3

10x^3 y + 21x^2 y^2 + 9xy^3

2a^3 b +11a^2 b^2 - 21ab^3

6x^3 y + 7x^2 y^2 - 20xy^3

2x^4 -512

243 - 3y^4

625m^4 - 16

Thanks so much!