Compare and contrast a postulate , theorem and a conjecture

Please HELP ME

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

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16

Which ratios are equivalent to 10: 16? check all that apply. 30 to 48 25: 35 8: 32 5 to 15