/2a+1/+4a2-4ab+b2=0
|2a+1|+(2a-b)²=0
∴2a+1=0
2a-b=0
∴a=-1/2
b=-1
∴a2{a-b}-b2{b-a]
=a²(a-b)+b²(a-b)
=(a-b)(a²+b²）
=(-1/2+1)(1/4+1)
=5/8