[tex]\left\{\begin{array}{ccc}y=x-3\\2x-4y=8\end{array}\right\\\\subtitute\ y=x-3\ to\ the\ second\ equation:\\\\2x-4(x-3)=8\\2x-4(x)-4(-3)=8\\2x-4x+12=8\\-2x+12=8\ \ \ \ |subtract\ 12\ from\ both\ sides\\-2x=-4\ \ \ \ |divide\ both\ sides\ by\ (-2)\\\boxed{x=2}\\\\put\ value\ of \x-2\ to\ the\ equation\ y=x-3:\\y=2-3=-1\\\\Answer:\boxed{x=2\ and\ y=-1}[/tex]
