已知5m-3n-7=-7,求(x-y)^m*(y-x)^4m/(x-y)^3n的值(x-y≠0)
问题描述：
已知5m-3n-7=-7,求(x-y)^m*(y-x)^4m/(x-y)^3n的值(x-y≠0)
答
5m-3n-7=-7
5m-3n=0
(x-y)^m*(y-x)^4m/(x-y)^3n
=(x-y)^m*(x-y)^4m/(x-y)^3n
=(x-y)^(m+4m-3n)
=(x-y)^(5m-3n)
=(x-y)^0
=1