Answer:
2.

Explanation:
We have to find the polynomial can be simplified to a difference of squares.
1.

Combine like terms

10 in
is not a perfect square number because when a number end with one zero then the number is not perfect square number.
Therefore, it can not be simplified to a difference of squares.
2.


Combine like terms

Hence, the polynomial can be simplified as difference of squares.
3.

Combine like terms


Hence, the polynomial can not be simplified as difference of squares because the polynomial can be simplified as sum of squares.
4.

Combine like terms



24 is not a perfect square number because when factorize 24 then 2 and 3 are not paired.
Hence, the polynomial can not be simplified as difference of squares.