Answer:
The simplified form is
.
is the excluded value for the given expression.
Step-by-step explanation:
Given:
The expression given is:

Let us simplify the numerator and denominator separately.
The numerator is given as 
2 is a common factor in all the three terms. So, we factor it out. This gives,

Now, 
Therefore, the numerator becomes 
The denominator is given as: 
Factoring out 3, we get

Now,
is of the form 
So, 
Therefore, the denominator becomes 
Now, the given expression is simplified to:

There is
in the numerator and denominator. We can cancel them only if
as for
, the given expression is undefined.
Now, cancelling the like terms considering
, we get:

Therefore, the simplified form is 
The simplification is true only if
. So,
is the excluded value for the given expression.