Plz help me find perimeter and area you do not have to do both but plz help no links

Rachel reads 1/5 of the pages of a book plus 12 pages on the first day. on the second day, she reads 1/4 of the remaining pages plus 15 pages. on the third day, she reads 1/3 of the remaining pages plus 18 pages. on the fourth day, she reads the remaining 70 pages. how many total pages are in the book?

What are “like terms”? why can we only add like terms?

In the diagram below? p is circumscribed about quadrilateral abcd. what is the value of x