You can easily tell if Keisha will finish reading the book by this equation:
y = 325 - 25x
where y is the number of pages left, and x is the number of days. A point slope for has a standard form of y - y1 = m(x - x1). Thus, we arrange it in this manner:
y = 25(13 - x)
Then, substitute x = 10:
y = 25(13 - 10)
y = 75
So, Keisha will not be able to finish the book in 10 days. There are still 75 pages left to read.