[tex]2x + 19y = 128 \\ 2x = 128 - 19y \\ x = 64 - \frac{19}{2} y[/tex]
Substitute that into
[tex] - 15(64 - \frac{19}{2} y) - 19y = 28 \\ - 960 + 142.5y - 19y = 28 \\ 123.5y = 988 \\ y = 8[/tex]
Insert y into
[tex]x = 64 - \frac{19}{2} (8) \\ x = 64 - 76 \\ x = - 12[/tex]
x = - 12, y = 8
Hope this helps. - M