\[y = 2x - 6\]
\[y = 0\ \ \ \ \ \ \ \ \ \ \ \ \ y < 0\]
\[2x - 6 = 0\ \ \ \ \ \ \ \ 2x - 6 < 0\]
\[2x = 6\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2x < 6\]
\[x = 3\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ x < 3.\]