7. On the coordinate plane, there are two distinct points $P$ and $Q$, where point $P$ has coordinates $(s, t)$. The perpendicular bisector $L$ of segment $\overline{PQ}$ has equation $3x - 4y = 0$. Which of the following options are correct? (1) Vector $\overrightarrow{PQ}$ is parallel to vector $(3, -4)$ (2) The length of segment $\overline{PQ}$ equals $\frac{|6s - 8t|}{5}$ (3) Point $Q$ has coordinates $(t, s)$ (4) The line passing through $Q$ and parallel to line $L$ must pass through point $(-s, -t)$ (5) If $O$ denotes the origin, then the dot product of vector $\overrightarrow{OP} + \overrightarrow{OQ}$ and vector $\overrightarrow{PQ}$ must be 0
7. On the coordinate plane, there are two distinct points $P$ and $Q$, where point $P$ has coordinates $(s, t)$. The perpendicular bisector $L$ of segment $\overline{PQ}$ has equation $3x - 4y = 0$. Which of the following options are correct?\\
(1) Vector $\overrightarrow{PQ}$ is parallel to vector $(3, -4)$\\
(2) The length of segment $\overline{PQ}$ equals $\frac{|6s - 8t|}{5}$\\
(3) Point $Q$ has coordinates $(t, s)$\\
(4) The line passing through $Q$ and parallel to line $L$ must pass through point $(-s, -t)$\\
(5) If $O$ denotes the origin, then the dot product of vector $\overrightarrow{OP} + \overrightarrow{OQ}$ and vector $\overrightarrow{PQ}$ must be 0