Name each polygon . then tell whether it is a regular polygon or not a regular polygon

Aregular pentagon with a perimeter of 21 inches is dilated by a scale factor of 5/3 to create a new pentagon. what is the perimeter of the new pentagon?

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a