The gradient of the line joining the points on the curve $y = x^2 + 2x$ whose abscissae are $1$ and $3$,is

If the line $y = mx + c$ passes through the points $(2, 4)$ and $(3, -5)$,then:

The equation of the line passing through the points $(-7, 8)$ and $(5, 2)$ is . . . . . . .

$A$ line passes through the point $(1, 2)$ and makes an angle of $60^{\circ}$ with the $x$-axis. The coordinates of the points on this line at a distance of $3$ units from the point $(1, 2)$ are:

The equation of the line passing through $(1, 2)$ and parallel to the line $y = 3x - 1$ is

If $(a, -2a), a > 0$ is the midpoint of a line segment intercepted between the coordinate axes,then the equation of the line is