The first expression simplifies as follows:

2a^-5 b^2 3a^-2 b^-5
= 2 3 a^-5 a^-2 b^2 b^-5
= 6 a^-7 b^-3
= 6 a^-7 b^-3
= 6 / a^7 * b^3

Therefore, 2a^-5 b^2 3a^-2 b^-5 simplifies to 6 / a^7 b^3.

The second expression simplifies as follows:

(1/2mn^-3)^-2
= (2mn^3)^2
= 2^2 m^2 n^6
= 4 m^2 * n^6

Therefore, (1/2mn^-3)^-2 simplifies to 4m^2n^6.