Answer
$d(P,\ Q)=\sqrt{(x_{2}-x_{1})^{2}+(m_{2}x_{2}-m_{1}x_{1})^{2}}$
Work Step by Step
To find the distance between two points $(x_1,y_1)$ and ($x_2$,$y_2$), we use the distance formula:
$d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$
We find the distance from point $P(x_1,m_1x_1)$ to $Q(x_2,m_2x_2)$:
$d(P,\ Q)=\sqrt{(x_{2}-x_{1})^{2}+(m_{2}x_{2}-m_{1}x_{1})^{2}}$