What is the prime factorization of 2,800

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 is the value of x? enter your answer in the box. photo attached.

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.