When
the value of the expression becomes undefined so it is the non-permissible replacement for the expression.
Explanation:
Step 1:
To determine the non-permissible replacement we substitute x with the values of 6, 3, -3, and -6.
When
,
When
,
When
,
When
, any value, when divided by a zero, becomes undefined.
Step 2:
The values of options a, b, and c all have numerical values.
When
the value of the expression becomes undefined so it is the non-permissible replacement for the expression.