a: \(=x^2+10x+25+y^2+2y+1\)
\(=\left(x+5\right)^2+\left(y+1\right)^2\)
b: \(=4x^2-4xz+z^2+z^2-2z+1\)
\(=\left(2x-z\right)^2+\left(z-1\right)^2\)
c: \(=x^2-6x+9+y^2+4y+4\)
\(=\left(x-3\right)^2+\left(y+2\right)^2\)
d: \(=x^2+2xy+y^2+y^2+2y+1\)
\(=\left(x+y\right)^2+\left(y+1\right)^2\)