l a+3 l+(2a+b)^2=0
|a+3|>=0
(2a+b)^2>=0
所以 a+3=0
2a+b=0
解得a=-3,b=6
则：
(2ba^3)x(2ab+1)-[a^2 x (-2ab)^2]
=2ba^3x(2ab+1)-(4a^4b^2)
=2ba^3x(2ab+1-2ab)
=2ba^3
=2x6x(-3)^3
=-324