Question

Please help ASAP

Which expressions are differences of squares?
Select each correct answer.
a^2+1
x^2−169
h^2−20
t^2−4

Answer 1

differnce is
a²-b²

frst one is not, that is sum
2nd one is, x²-13²
3rd on e is not, 20 is not a perfect square (but you could do h²-(√20)²)
4th one is t²-2²


2nd and 4th