Is the polynomial a difference of squares?

select difference of squares or not a difference of squares for each polynomial.

y^4−144
5m^2n^2−25
16x2−49
p^2−q^4

Difference of squares are terms of the form

(a^2 - b^2) = (a+b)(a-b)

Case a

y^4−144 = (y^2 - 12) (y^2 + 12)  = (a-b)(a+b)

Difference of squares

Case b

5m^2n^2−25 = 5 (m^2 n^2 - 5) ≠ (a+b)(a-b)

Not a difference of squares

Case c

16x2−49 = (4 x - 7) (4 x + 7)  = (a-b)(a+b)

Difference of squares

Case d

p^2−q^4 = (p - q^2) (p + q^2) = (a-b)(a+b)

Difference of squares

the answer to this question is in the pic

if a = 1,   and b = 2, then the answer is 47.99999999. if you round that to the nearest whole number, the answer is 48.