so a normal diff of squares is (a^2-b^2)
factored it is
(a+b)(a-b)
and we know when exponents are multiplied together they’re added, so if you know that the b value is a square of a number, then look at the exponent
look at 1 y^4 is a square since y^2 x y^2 = y^4
and 144 is the square of 12
both terms can be square rooted and there is a - sign, meaning a diff of squares:
(y^2-12)(y^2+12)
the second one is the only one that is not a difference of squares
sorry i know i’m bad at explaining things