To find the value of \( x \) that makes the equation \( 14 = \frac{7x}{9} + 4x \) undefined, we first need to manipulate the equation to isolate \( x \).
Let's rewrite the equation:
\[ 14 = \frac{7x}{9} + 4x \]
Next, we'll simplify by finding a common denominator for the terms on the right:
\[ 4x = \frac{36x}{9} \]
Now substituting this back into the equation gives:
\[ 14 = \frac{7x}{9} + \frac{36x}{9} \]
Combine the fractions:
\[ 14 = \frac{7x + 36x}{9} \]
This simplifies to:
\[ 14 = \frac{43x}{9} \]
Now, we can multiply both sides by 9 to eliminate the fraction:
\[ 14 \times 9 = 43x \]
\[ 126 = 43x \]
Now, divide both sides by 43:
\[ x = \frac{126}{43} \]
This value will not make the equation undefined, as it is simply a value for \( x \).
In rational expressions, they can become undefined when the denominator equals zero. However, in this equation, there are no denominators that depend on \( x \) that could potentially become zero, so the equation itself does not indicate any restrictions on \( x \).
Therefore, none of the suggested responses indicate an undefined value in this context. All options provided seem to reflect specific values of \( x \) rather than the absence of restrictions.
If the question was looking for which values would lead to the function being undefined, none would fit this scenario since this equation does not restrict \( x \) to make it undefined.
Thus, the correct conclusion is that there are no undefined values for this equation regarding \( x \).