已知实际x、y满足2x的平方+6xy+9y的平方-2x+1=0,试求x、y,急,还1题

1:2x^2+6xy+9y^2—2x+1=0
x^2+6xy+9y^2+[x^2-2x+1]=0
[x+3y]^2+[x-1]^2=0
x+3y=0
x-1=0
x=1,y=-1/3
2:x^2-4x+5=x^2-4x+4+1=(x-2)^2+1
(x-2)^2>=0
所以代数式恒大于0