带上你耐心的分析,全解六题.分解因式 ,

1、(x-y)+y²(y-x)=(y-x)(y²-1)
=(y-x)(y-1)(y+1)
2、x²-z²+xy+y²（题目有误,无法分解）
3、4m³-16m²+16m=4m(m²-4m+4)=4m(m-2)²
4、(x+y)²-4(x+y)-12=[(x+y)-6]*[(x+y)+2]=(x+y-6)(x+y+2)
5、1/2m²-2n²=(1/2)(m²-4n²)=(1/2)(m-2n)(m+2n)
6、(a²-3)²-4a²=[(a²-3)-2a]*[(a²-3)+2a]
=(a²-2a-3)(a²+2a-3)
=(a-3)(a+1)(a+3)(a-1)

(x-y)+y²(y-x)=(x-y)-y²(x-y)=(x-y)(1-y²)=(x-y)(1+y)(1-y)
x²-z²+2xy+y²=(x+y)²-z²=(x+y-z)(x+y+z)
4m³-16m²+16m=4m(m²-4m+4)=4m(m-2)²
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