만약 x2-2x+10+y2+6y=0,구(2x+y)2

만약 x2-2x+10+y2+6y=0,구(2x+y)2

x2-2x+10+y2+6y=0
x²-2x+1+y²+6y+9=0
(x-1)²+(y+3)²=0
x-1=0
y+3=0
∴x=1
y=-3
(2x+y)²=(2-3)²=1