\(2x^2+2xy+y^2+2x+1=0\)
\(\Leftrightarrow y^2+2xy+2x^2+2x+1=0\)
\(\Leftrightarrow y^2+2xy+x^2+x^2+2x+1=0\)
\(\Leftrightarrow\left(y+x\right)^2+\left(x+1\right)^2=0\)
\(\Rightarrow x+1=0\Rightarrow x=\left(-1\right)\)
\(\Rightarrow y+x=0\Leftrightarrow y-1=0\Rightarrow y=1\)
Vậy giá trị của \(x\)là \(\left(-1\right)\)