Can you explain/show the process used to reach this answer?

#1.

(2b^4 c^-2)^5 (3b^-3 c^-4)^-2

= (32 b^20 c^-10) (9 b^6 c^8) = 32 b^26/9c^2 , How did it turn into a

fraction and not, 288 b^26 c^2?

#2 I started these 2 problems and do not knows how to finish them-

Can you show me how to do it?

(3 b^5 c^-2)^3 / 2^-1 b^-3 c = 27 b^15 c^-6 / 2^-1 b^-3 c = ?

(2b^-4 c)-3/ (2b^2 c^-5)^2 = -8b^12c^-3/4b^4c^-10 = ?