The coordinate of mid-point of $P Q$ is
$$
M\left(\frac{-\frac{7}{5}+1}{2}, \frac{-\frac{6}{5}+2}{2}\right) \text { i.e., } \quad\left(-\frac{1}{5}, \frac{2}{5}\right)
$$
Now, slope of $P Q$ is
$$
m=\frac{2+\frac{6}{5}}{1+\frac{7}{5}}=\frac{16}{12}=\frac{4}{3}
$$
Since, the required line is perpendicular to $P Q$ and passing through $M\left(-\frac{1}{5}, \frac{2}{5}\right)$
$\therefore$ Equation of line is
$$
\begin{array}{rlrl}
& y-\frac{2}{5}=- & \frac{1}{4 / 3}\left(x+\frac{1}{5}\right) \\
& \frac{5 y-2}{5} & =-\frac{3}{4} \frac{(5 x+1)}{5} \\
& 20 y-8 & =-15 x-3 \\
\Rightarrow & & 20 y+15 x & =5 \\
\text { or } & & 4 y+3 x & =1
\end{array}
$$