Answer:

Explanation:
we know that
Every difference of squares problem can be factored as follows:

If the polynomial represent a difference of squares every number must be a perfect square (Remember that a number is a perfect square if its square root is an integer.)
Verify each case
case 1) we have

In this case both numbers are perfect square
so

therefore
The polynomial represent a difference of squares
case 2) we have

In this case 8 is not a perfect square
therefore
The polynomial not represent a difference of squares
case 3) we have


In this case both numbers are perfect square
but is a sum of squares
therefore
The polynomial not represent a difference of squares
case 4) we have


In this case 2 is not a perfect square
therefore
The polynomial not represent a difference of squares