They are giving us the following expression to calculate its canonical form.
To do this we will complete the value that allows us to perform the squared product.
[tex]\begin{gathered} y=x^2+12x+36-36+7 \\ y=(x+6)^2-36+7 \\ y=(x+6)^2-29 \end{gathered}[/tex]The answer would be :
[tex]y=(x+6)^2-29[/tex]