
The $(x, y)$ coordinates of vertices $\mathrm{P}, \mathrm{Q}$ and $\mathrm{R}$ of a parallelogram $\mathrm{PQRS}$ are $(-3,-2),(1,-5)$ and $(9,1)$, respectively. If the diagonal $\mathrm{SQ}$ intersects the $x$-axis at ( $a, 0$ ), then the value of $\mathrm{a$ is
- $\dfrac{27}{7}$
- $\dfrac{10}{3}$
- $\dfrac{13}{4}$
- $\dfrac{29}{9}$