|a+1|+4a^2+4ab+b^2=0 |a+1|+(2a+b)^2=0 那么a+1=0,2a+b=0 ∴a=-1,b=-2a=2 ∴(a+1/2b)^2-(a-1/2b)^2-a^2(-2ab)^2 =[(a+1/2b)+(a-1/2b)][(a+1/2b)-(a-1/2b)]-4a^4b^2 =2ab-4a^4b^2 =-4-16 =-20,4,
