To determine if \((2, 4)\) is a solution to the given system of equations, we need to substitute \(x = 2\) and \(y = 4\) into both equations and check if both equations hold true.
We start by substituting \(x = 2\) and \(y = 4\) into the first equation:
\[
y = -\frac{1}{2} x + 5
\]
Substituting the values:
\[
4 = -\frac{1}{2} \cdot 2 + 5
\]
Calculating the right side:
\[
4 = -1 + 5
\]
This simplifies to:
\[
4 = 4
\]
Thus, the first equation is satisfied.
Next, we substitute \(x = 2\) and \(y = 4\) into the second equation:
\[
-8x - 4y = -24
\]
Substituting the values:
\[
-8 \cdot 2 - 4 \cdot 4 = -24
\]
Calculating the left side:
\[
-16 - 16 = -32
\]
This simplifies to:
\[
-32 \neq -24
\]
Thus, the second equation is not satisfied.
Since the point \((2, 4)\) satisfies the first equation but does not satisfy the second equation, it is not a solution to the system of equations.