若m^2+n^2-m-4n+4/1/4=0,求m^n-mn的值
问题描述：
若m^2+n^2-m-4n+4/1/4=0,求m^n-mn的值
答
m^2+n^2-m-4n+4/1/4=0
(m^2-m+1/4)+(n^2-4n+4)=0
(m-1/2)^2+(n-2)^2=0
m=1/2
n=2
m^n-mn=1/4-1=-3/4