Respuesta :

Answer:

-1/2

Step-by-step explanation:

The non permissible replacement of the variable in a certain expression is the value of x that will make the denominator of the expression zero. In this certain given, 

                               6x + 3 ≠ 0 

Solving for x, 

                                x ≠ -1/2

Thus, the answer is -1/2.