已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的值为?

已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的值为?
已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的值为?

已知x,y满足x²+y²-4x+6y+13=0则(3x+y)²-(3x+y)(3x-y)的值为?
x²+y²-4x+6y+13=0
x²-4x+4+y²+6y+9=0
(x-2)²+(y+3)²=0
x=2,y=-3
代入即可得出答案
(3x+y)²-(3x+y)(3x-y)=9-3x9=-18