The equation of the line parallel to the line $2x - 3y = 1$ and passing through the midpoint of the line segment joining the points $(1, 3)$ and $(1, -7)$ is:

The intercept cut off from the $y$-axis is twice that from the $x$-axis by a line,and the line passes through $(1, 2)$. Find its equation.

Find the equation of the line passing through $(4, 6)$ and parallel to the line $3x - 7y + 2 = 0$.

The equation of the line,which bisects the line segment joining the points $(2, -19)$ and $(6, 1)$ and is perpendicular to the line joining the points $(-1, 3)$ and $(5, -1)$,is

Find the equation of a line that makes an angle of $60^{\circ}$ with the $x$-axis and makes an intercept of $5$ units on the negative direction of the $y$-axis.

Let $O=(0,0)$. Let $A$ and $B$ be points on the $X$-axis and $Y$-axis respectively such that $\angle OBA = 60^{\circ}$. Let $D$ be a point in the first quadrant such that $\triangle OAD$ is an equilateral triangle. Then,the slope of $DB$ is