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 given that the slope of the line is $\frac{2}{7}$.
$\therefore$$\frac{-2}{-3-k}$ =$\frac{2}{7}$
$\Rightarrow 2(-3-k)=-14$
$\Rightarrow -6-2k=-14$
$\Rightarrow -2k=-8$
$\therefore$ k = 4