Lisa represented the phrase '9 less than a number' with the expression 9-n. Is her expression correct? Explain why or why not.

Camille is preparing for her english test by typing up the notes she recorded in the margins of her 98-page workbook. she already started typing her notes, and got through the first 14 pages. if camille types for x hours at a rate of 21 pages per hour, which equation represents the number of pages she has typed, and how many hours will it take to complete the task?