What is the undefined value for 22=4+ 5x/ 9x−6

To find the undefined value in the equation

\[
22 = \frac{4 + 5x}{9x - 6},
\]

we need to determine when the denominator is equal to zero because division by zero is undefined.

Set the denominator to zero:

\[
9x - 6 = 0.
\]

Now, solve for \(x\):

\[
9x = 6,
\]

\[
x = \frac{6}{9} = \frac{2}{3}.
\]

Thus, the undefined value for the equation is

\[
\frac{2}{3}.
\]