(-x-+2) i need to know the work and answer

What's the difference between: x≥0 and nonnegative integer. ?

Franklin neason earns $5,250 a month as a sales manager. what is his semimonthly salary? a.$10,500b.$5,250c.$2,365d.$2,625

Shryia read a 481 -page-long book cover to cover in a single session, at a constant rate. after reading for 1.5 hours, she had 403 pages left to read. how fast was shryia reading? pages per hour how long did it take her to read the entire book? hours plz i realy need this