\[\boxed{\text{206\ (206).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\frac{x - y}{y} = 2\]
\[\frac{x}{y} - \frac{y}{y} = 2\]
\[\frac{x}{y} - 1 = 2\]
\[\frac{x}{y} = 2 + 1 = 3\]
\[x = 3y.\]
\[Подставим:\]
\[\frac{3x^{2} - xy + 6y^{2}}{y^{2}} =\]
\[= \frac{3(3y)^{2} - 3y \cdot y + 6y^{2}}{y^{2}} =\]
\[= \frac{27y^{2} - 3y^{2} + 6y^{2}}{y^{2}} = \frac{30y^{2}}{y^{2}} =\]
\[= 30.\]
\[Ответ:30.\]