A band group is having a carwash fundraiser to earn money. The group spent $25 on soap. Each car is charged $7. Let c represent the number of cars and a represent the amount of money earned. Write an equation that shows the relationship

Question

a=

Answer 1

To express the relationship between the amount of money earned (a) and the number of cars washed (c), we start with the following points:

1. The band spends $25 on soap, which is a fixed cost.
2. Each car washed generates $7 in revenue.

The total amount earned (a) can be represented by the revenue from washing cars after covering the initial cost. The revenue from washing \( c \) cars would be \( 7c \).

However, since they had an initial expense of $25, the equation for the amount of money earned after covering the costs can be written as:

\[ a = 7c - 25 \]

This equation shows that the total amount of money earned (a) is equal to the revenue from washing \( c \) cars at $7 each, minus the $25 spent on soap.