Answer:
Step-by-step explanation:
The equation is given by (a - 12)x = a + 8.
In order to get the solution of the equation, that is the value of x, the above equation is needs to be divided by a - 12. (a - 12) will be in the denominator.
The solution can not be found, if the value of a - 12 will be 0, that is a = 12.