\(\displaystyle{y}={\left({x}+{3}\right)}^{{2}}\)

\(\displaystyle{\left(-{2}{x}-{6}\right)}^{{2}}={\left[-{2}{\left({x}+{3}\right)}\right]}^{{2}}={\left(-{2}\right)}^{{2}}{\left({x}+{3}\right)}^{{2}}\)

=4y

\(\displaystyle{\left(-{2}{x}-{6}\right)}^{{2}}={\left[-{2}{\left({x}+{3}\right)}\right]}^{{2}}={\left(-{2}\right)}^{{2}}{\left({x}+{3}\right)}^{{2}}\)

=4y