(x+y-z)(x-y+z)-(y+z-x)(z-x-y)公因式 过程(x+y-z)(x-y+z)-(y+z-x)(z-x-y)=(x+y-z)(x-y+z)+(y+z-x)

问题描述:

(x+y-z)(x-y+z)-(y+z-x)(z-x-y)公因式 过程(x+y-z)(x-y+z)-(y+z-x)(z-x-y)=(x+y-z)(x-y+z)+(y+z-x)
为什么变成加号只有后面的变号

(x+y-z)(x-y+z)-(y+z-x)(z-x-y)公因式 过程(x+y-z)(x-y+z)-(y+z-x)(z-x-y)=(x+y-z){(x-y+z)+(y+z-x)}(x+y-z)(x-y+z)-(y+z-x)(z-x-y)=(x+y-z)(x-y+z)+(-1)(y+z-x)(z-x-y)=(x+y-z)(x-y+z)+(y+z-x)(-1)(z-x-y)=(x+y-z)(...