m*m+n*n-6m+10n+34=0,求m+n的值
问题描述：
m*m+n*n-6m+10n+34=0,求m+n的值
答
m*m+n*n-6m+10n+34=0
m*m-2*m*3+n*n+2*n*5+34=0(34=9+25)
m*m-2*m*3+3*3+n*n+2*n*5+5*5=0
(m-3)^2+(n+5)^2=0
M-3=0且n+5=0
m=3,n=-5
m+n=-2