Question

(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z)

Answer 1

(x-y)(y-z)(z-x)/(z-y)(y-x)(x-z)
=(x-y)(y-z)(z-x)/(y-z)(x-y)(x-z)
=(z-x)/(x-z)
=-(x-z)/(x-z)
=-1
分析：把分母的每一个括号里提出一个负号后，分子和分母就一样了，就是分母多了一个“负号”，结果就是负一