[tex]0.3(6 - 3y) = 4.5 - 0.8(y - 9)[/tex]

[tex]1.8 -0 .9y = 4.5 - 0.8y + 7.2[/tex]

[tex] - 0.9y + 0.8y = 4.5 + 7.2 - 1.8[/tex]

[tex] - 0.1y = 9.9[/tex]

[tex]y = - \frac{9.9}{0.1} [/tex]

[tex]y = - 99[/tex]