\[\boxed{\text{275\ (275).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[y = 0,3x - 6\ \ \]
\[Выразим\ x\ через\ y:\]
\[y + 6 = 0,3x\]
\[если\ \ y = - 6:\]
\[x = \frac{- 6 + 6}{0,3} = 0.\]
\[если\ \ y = - 3:\]
\[x = \frac{- 3 + 6}{0,3} = \frac{3}{0,3} = 10.\]
\[если\ \ y = 0:\]
\[x = \frac{0 + 6}{0,3} = \frac{6}{0,3} = 20.\]