Question

If the slope of the line joining the
points P (k,0) and Q (-3,-2) is $\frac{2}{7}$,
then k = ______________.

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

The correct option is D 4

Given points are P (k,0) and Q (-3,-2).

$\because$ Slope of the line joining the two points $(x_1,y_1)$ and $(x_2,y_2)$ is given by $\frac{y_2-y_1}{x_2-x_1}$.

$\therefore$ Slope of line PQ = $\frac{(-2)-0}{(-3)-k}$
= $\frac{-2}{(-3)-k}$

Also, the given slope of the line is $\frac{2}{7}$.
$\therefore$$\frac{-2}{(-3)-k}$ =$\frac{2}{7}$
$\Rightarrow 2\left[\right(-3)-k]=-14$
$\Rightarrow -6-2k=-14$
$\Rightarrow -2k=-8$
$\therefore$ k = 4