Step 1: Rewrite the equation of the hyperbola.
We are given the equation of the hyperbola:
\[
16x^2 - 9y^2 = 144
\]
Divide both sides by 144 to simplify the equation:
\[
\frac{x^2}{9} - \frac{y^2}{16} = 1
\]
This is the standard form of the equation of a hyperbola.
Step 2: Determine the conjugate axis.
The conjugate axis of a hyperbola is perpendicular to the transverse axis. Since the transverse axis is along the x-axis, the conjugate axis is along the y-axis.
Step 3: Use the given conjugate line.
We are told that the conjugate line is \( x = 2y \). For a hyperbola, the conjugate line is related to the equation of the hyperbola through the coordinates of the points on the conjugate axis.
Step 4: Find the relationship between \( x \) and \( y \).
The equation \( x = 2y \) implies:
\[
y = \frac{x}{2}
\]
Substitute this into the equation of the hyperbola:
\[
\frac{x^2}{9} - \frac{\left( \frac{x}{2} \right)^2}{16} = 1
\]
Simplifying:
\[
\frac{x^2}{9} - \frac{x^2}{64} = 1
\]
Step 5: Solve for the value of \( y \).
Multiply the entire equation by the least common denominator, 576:
\[
64x^2 - 9x^2 = 576
\]
Simplifying:
\[
55x^2 = 576 \quad \implies \quad x^2 = \frac{576}{55}
\]
Thus, the conjugate axis is related by the equation \( y = \frac{32x}{9} \).