Question

If $P(a/3,4)$ is the midpoint of the line segment joining the points $Q(-6,5)$ and $R(-2,3)$, then the find the value of $a$.

Answer 1

P is mid-point of QR$\to P_x=\frac{a}{3}=\left(\frac{-6-2}{2}\right)$

$\Rightarrow 2a=-2$

$\Rightarrow a=-12$.