Step 1: Write the condition of equidistance.
\[
QP = QR
\]
Using the distance formula,
\[
\sqrt{(0-5)^2 + (1-(-3))^2} = \sqrt{(0-x)^2 + (1-6)^2}.
\]
Step 2: Simplify both sides.
Left side: $(0-5)^2 = 25$, $(1+3)^2 = 16$
\[
QP = \sqrt{25+16} = \sqrt{41}.
\]
Right side: $(0-x)^2 = x^2$, $(1-6)^2 = 25$
\[
QR = \sqrt{x^2 + 25}.
\]
Step 3: Equating and solving.
\[
\sqrt{41} = \sqrt{x^2 + 25} \ \Rightarrow\ 41 = x^2 + 25 \ \Rightarrow\ x^2 = 16.
\]
\[
x = \pm 4.
\]
Conclusion:
The values of $x$ are $4$ and $-4$.
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.