分解因式(x-y)³+4（y-x）,（x+y)²+4（y+x+1）,x²-4y²+12yz-9z²
问题描述：
分解因式(x-y)³+4（y-x）,（x+y)²+4（y+x+1）,x²-4y²+12yz-9z²
答
1. (x-y)(x-3)(x+1)
2.[(x+y)+2]的平方
3.[x-(2y-3z)][x+(2y-3z)]
答
1
=(x-y)[(x-y)^2-4]=(x-y)(x-y+2)(x-y-2)
2
=(x+y+2)^2
3
=x^2-(4y^2-12yz+9z^2)
=x^2-(2y+3z)^2
=(x+2y+3z)(x-2y-3z)
答
(x-y)³+4（y-x）=(x-y)[(x-y)²-4]=(x-y)(x-y+2)(x-y-2)（x+y)²+4（y+x+1）=(x+y)²+4(x+y)+4=(x+y+2)²x²-4y²+12yz-9z²=x²-(4y²-12yz+9z²)=x²-(2y-3z)...