Respuesta :

we just need to replace

[tex]\begin{gathered} \frac{abc}{3b}=3 \\ \frac{a(1)(9)}{3(1)}=3 \\ \frac{9a}{3}=3 \\ 9a=3\times3 \\ a=\frac{9}{9} \\ a=1 \end{gathered}[/tex]