[tex]\begin{gathered} 6x-9=y \\ y=-3x \\ \text{substitute y = -3x into first equation} \\ 6x-9=-3x \\ 6x+3x=9 \\ 9x=9 \\ x=\frac{9}{9} \\ x=1 \end{gathered}[/tex]
substitute x = 1 into y = -3x
[tex]\begin{gathered} y=-3(1_{}) \\ y=-3 \end{gathered}[/tex]
Hence, x = 1. y= -3