`a)`\(x^2+y^2+10x+2y+26=\left(x^2+10x+25\right)+\left(y^2+2y+1\right)=\left(x+5\right)^2+\left(y+1\right)^2\ge0\)
`b)`\(x^2-2xy+2y^2+2y+1=\left(x^2-2xy+y^2\right)+\left(y^2+2y+1\right)=\left(x-y\right)^2+\left(y+1\right)^2\ge0\)
`c)`\(x^2-8xy+1+2y+17y^2=\left(x^2-8xy+16y^2\right)+\left(y^2+2y+1\right)=\left(x-4y\right)^2+\left(y+1\right)^2\ge0\)