help plz

We can factor the denominator first: (a+2)(a-2), and leave the numerator as it is: a+3. Now, think about what undefined means, and see what value of x can fit in.

Thanks Tertre,   

More of a hint: you cannot divide by 0, that is impossible. So if the bottom is 0 the answer would be undefined.

As tertre and Melody said, this will be undefined whenever the denominator   = 0

And the denominator factors as ( x + 2) ( x - 2)

So   either

x +  2   =  0  ⇒  x  = -2

or

x  - 2   = 0 ⇒   x  =  2

So   [ -2,  2  ]  make the expression undefined