Please help this is due tomorrow :,)

Plz determine whether the polynomial is a difference of squares and if it is, factor it. y2 – 196 is a difference of squares: (y + 14)2 is a difference of squares: (y – 14)2 is a difference of squares: (y + 14)(y – 14) is not a difference of squares

Which two undefined geometric terms always describe figures with no beginning or end?

Hello, i need compare km^2 and km. what's difference in this?