已知a+b+2=0,则代数式(a²-b²)²-8(a²+b²)=

已知a+b+2=0,则代数式(a²-b²)²-8(a²+b²)=
已知a+b+2=0,则代数式(a²-b²)²-8(a²+b²)=

已知a+b+2=0,则代数式(a²-b²)²-8(a²+b²)=
(a²-b²)²-8(a²+b²)=
=(a+b)²(a-b)²-8(a²+b²)
=(-2)²(a²-2ab+b²)-8(a²+b²)
=4a²-8ab+4b²-8a²-8b²
=-4a²-8ab-4b²
=-4(a²+2ab+b²)
=-4(a+b)²
=-4×(-2)²
=-16