Respuesta :

[tex]\begin{gathered} (3x-6)\cdot(2x+8) \\ 6x^2+24x-12x-48 \\ 6x^2+12x-48 \\ \end{gathered}[/tex]

x=3

[tex]\begin{gathered} 6\cdot3^2+12\cdot3-48 \\ 6\cdot9+36-48 \\ 54+36-48=42 \end{gathered}[/tex]