Answer:
x = -3
Explanation:
The given rational expression is

This expression is undefined when the denominator equal to zero.
So we have to set the denominator equal to zero and find the value of "x" where the expression is undefined.
Here the denominator is 3 + x.
Set the denominator equal to zero and find the value of x.
3 + x = 0
Subtract 3 on both sides, we get
3 + x - 3 = 0 - 3
x = -3
When x = -3, the given rational expression is undefined.