因式分解:(x²+y²-z²)²-4x²y²
问题描述：
因式分解:(x²+y²-z²)²-4x²y²
答
(x²+y²-z²)²-4x²y²=（x²+y²-z²+2xy)(x²+y²-z²-2xy)=[(x+y)²-z²][(x-y)²-z²]=(x+y+z)(x+y-z)(x-y+z)(x-y-z)
因式分解:(x²+y²-z²)²-4x²y²
(x²+y²-z²)²-4x²y²=（x²+y²-z²+2xy)(x²+y²-z²-2xy)=[(x+y)²-z²][(x-y)²-z²]=(x+y+z)(x+y-z)(x-y+z)(x-y-z)