Question

Write an equation to represent each scenario, where x represents the number of months and y represents the total charge. Scenario 1: Des Tunes charges adults $15 per month. Scenario 2: Des Tunes charges students a $20 sign-up fee and then $5 per month.

Answer 1

Adults: 15x Students: 5x + 20

Explanation:

The number before each x is the cost per month. Since the x axis represents months, and the y axis represents total charge, we would simply write the adults equation as 15x. Same thing with the students, except they have a sign-up fee. This means that they spend an initial $20 before even spending their first $5 a month. We would represent that with a positive y-intercept. That's why the students equation is 5x + 20.