x^2+y^2-6x-4y+5=0 ,（x-3)^2+（y-2)^2=8 ,与x+y+3=0平行直线设为x+y+a=0 ,点（3,2)到该直线距离为8^1/2,8=|3+2+a|^2/2,a=-1或a=-9,直线为x+y-1=0或x+y-9=0.