The length of the perpendicular from the origin to a line is $7$ and the line makes an angle of $150^{\circ}$ with the positive direction of the $y$-axis. Find the equation of the line.

If the midpoints of the sides $BC, CA$ and $AB$ of the triangle $ABC$ are $(1, 3), (5, 7)$ and $(-5, 7)$ respectively,then the equation of the side $AB$ is

If the normal form of the equation of a straight line $4x + 3y + 2 = 0$ is $x \cos \alpha + y \sin \alpha = p$ and its intercept form is $\frac{x}{a} + \frac{y}{b} = 1$,then $\frac{p \sec \alpha}{ab} = $

The equation of the line passing through $(1, 2)$ and perpendicular to $3x + 4y + 5 = 0$ is

The owner of a milk store finds that he can sell $980$ liters of milk each week at Rs $14$ per liter and $1220$ liters of milk each week at Rs $16$ per liter. Assuming a linear relationship between selling price and demand,how many liters could he sell weekly at Rs $17$ per liter?

Find the number of integer values of $m$ such that the $x$-coordinate of the point of intersection of the lines $3x + 4y = 9$ and $y = mx + 1$ is an integer.