m^2-2m+n^2-n/3+(1+1/36)=0
(m^2-2m+1)+(n^2-1/3+1/36)=0
(m-1)^2+(n-1/6)^2=0
m-1=0且n-1/36=0
解得:m=1
n=1/36
所以:6n-m^2=-5/6