Dylan read 210 pages of a book in 5 days. He read 37 pages each day for the first 3 days He read y pages the fourth day. Which equation can be used to find p, the number of pages Dylan read on the fifth day?

p = 99 - y OR 99 - y = p

explanation:

day 1 = 37
day 2 = 37
day 3 = 37
day 4 = Y
day 5 = P

In the first 3 days dylan read 111 pages (37 x 3) that means he would of had to have to read 99 pages on days 4 & 5 altogether.

substitute what we know :-

y + p = 99

switch the equation round to show that we are trying to find the number of pages on day 5 :-

p = 99 - y