Question

Expression Real-World Scenario What does the variable represent?
r−10








21y





100a





17+s





57−r





48w

Answer 1

r − 10
- Scenario: You start with r dollars in your wallet and spend $10; you have r − 10 dollars left.
- Variable meaning: r = the amount of money you started with (in dollars).

21y
- Scenario: Concert tickets cost $21 each; buying y tickets costs 21y dollars.
- Variable meaning: y = the number of tickets.

100a
- Scenario: A factory makes 100 widgets per hour; in a hours it makes 100a widgets.
- Variable meaning: a = the number of hours of production.

17 + s
- Scenario: You already have 17 books and borrow s more from the library; you then have 17 + s books.
- Variable meaning: s = the number of additional books borrowed.

57 − r
- Scenario: A bus has 57 seats and r are occupied; 57 − r seats remain empty.
- Variable meaning: r = the number of occupied seats.

48w
- Scenario: You earn $48 per week from a part-time job; over w weeks you earn 48w dollars.
- Variable meaning: w = the number of weeks.