let's find y in terms of x:
[tex]\begin{gathered} 6(x-y)=19 \\ x-y=\frac{19}{6} \\ y=x-\frac{19}{6} \end{gathered}[/tex]Therefore:
[tex]y=x-\frac{19}{6}[/tex]If x=-1, then:
[tex]\begin{gathered} y=-1-\frac{19}{6} \\ =-\frac{25}{6} \end{gathered}[/tex]Then, y=-25/6
