To find the undefined value for the equation \( 22 = \frac{4 + 5x}{9x - 6} \), we first need to identify when the denominator equals zero, as division by zero is undefined.
The denominator is \( 9x - 6 \). We set it equal to zero and solve for \( x \):
\[ 9x - 6 = 0 \] \[ 9x = 6 \] \[ x = \frac{6}{9} \] \[ x = \frac{2}{3} \]
Thus, the undefined value is \( x = \frac{2}{3} \).
As requested, it is in reduced fraction form.
So, the final answer is: \[ \text{The undefined value is } \frac{2}{3}. \]