（1）
（-2a^2b)^2×（-2a^2b^2)^3
=4a^4b^2x(-8a^6b^6)
= -32a^10b^8
(2)
(-2x^2y)^3+8(x^2)^2×(-x)^2×（-y)^3
= -8x^6y^3+8x^4*x^2*(-y^3)
= -8x^6y^3-8x^6y^3
= -16x^6y^3
(3)
(-3a^3)^2×a^3+(-4a)^2×a^7-(5a^3)^3
=9a^6xa^3+16a^2xa^7-125a^9
=9a^9+16a^9-125a^9
= -100a^9