With a specific value of x, there is no inverse, right.does this mean there is no inverse?

You can try to invert the matrix. At some point, you will see that you have to divide by some expression with x inside. If this expression is 0, the operation is not valid, and you cannot invert the matrix.

Simple example:

B=

(1 0)

(0 x)

With , it is easy to invert. But if you set x=0, there is no inverse matrix.