Answer:
y = 480 - 52xStep-by-step explanation:
As per the given problem
She read a total of 480-402 = 78 pages in 1.5 hours
This means in one hour number of pages read = 78/1.5 = 52
After x hours number of pages read = 52x
Pages left after x hour of reading = 480-52x = y
Therefore
y = 480 - 52x