Respuesta :

[tex]\bf \begin{cases} x = -18\implies &x+18=0\\ x = -9\implies &x+9=0 \end{cases}\qquad \implies \qquad (x+18)(x+9)=\stackrel{y}{0} \\\\[-0.35em] ~\dotfill\\\\ ~\hfill \stackrel{\textit{using FOIL}}{x^2+27x+162}=y~\hfill[/tex]