Which of the following expressions cannot be written in the form 9kx, where k is an integer?194x9x94x3x34xSubmit

The expression that cannot be written in the form 9kx, where k is an integer, is 94x.

Here's why:

1. 194x: This can be written as 9(21.56x), so it fits the form 9kx.
2. 9x: This is already in the form 9kx, with k=1.
3. 94x: This cannot be written in the form 9kx, because 94 is not a multiple of 9.
4. 3x: This can be written as 9(0.33x), so it fits the form 9kx.
5. 34x: This can be written as 9(3.78x), so it fits the form 9kx.

So, the expression 94x cannot be written in the form 9kx, where k is an integer.