To find the undefined value for the equation \( 22 = \frac{4 + 5x}{9x - 6} \), we need to determine when the denominator is equal to zero, as this would make the expression undefined.
The denominator is:
\[ 9x - 6 \]
Setting the denominator equal to zero:
\[ 9x - 6 = 0 \]
Solving for \( x \):
\[ 9x = 6 \] \[ x = \frac{6}{9} = \frac{2}{3} \]
Thus, the undefined value is:
\[ \frac{2}{3} \]
So the answer is:
\[ \text{The undefined value is } \frac{2}{3}. \]