m²+n²-m-4n+4¼=0m²-m+1/4+n²-4n+4=0(m-1/2)²+(n-2)²=0m-1/2=0 m=1/2n-2=0 n=2m^n-mn=(1/2)²-2(1/2)=1/4-1=-3/4