Question

The equation d = 22.5n + 27.5 represents the amount of money, in dollars, that Kathryn earns for each sale she makes. The variable n represents the number of items sold, and the variable d represents the total amount of money earned. What is the number of items Kathryn must sell in order to earn $500?

A.) 10
B.) 17
C.) 21
D.) 23

Answer 1

21

Explanation:

`d = 22.5n + 27.5 \\ plugging \: d = 500 \\ 500 = 22.5n + 27.5 \\ 500 - 27.5 = 22.5n \\ 22.5n = 472.5 \\ n = (472.5)/(22.5) \\ n = 21`

Hence, Kathryn must sell 21 items in order to earn $500.

Answer 2

C.) 21

Explanation:

d = 22.5n + 27.5

Where d is the total amount of money earned and n is the number of items sold

Substitute:

500 = 22.5n + 27.5

We can substitute 500 for d because 500 is the total amount of money Kathryn wants to earn

Solve:

500 = 22.5n + 27.5

Subtract 27.5 on both sides:

500 = 22.5n + 27.5

-27.5 -27.5

472.5‬ = 22.5n

Divide by 22.5 on both sides:

472.5‬ = 22.5n

/22.5 /22.5

21 = n

Therefore, Kathryn must sell 21 items to make $500.