A movie theater showed an old, classic movie on Saturday and Sunday. Tickets cost c dollars for children under the age of 13 and d dollars for others.
On Saturday they sold 84 children's tickets and 157 tickets for others and collected $2,640 from ticket sales. On Sunday they sold 67 children's tickets and 134 other tickets and collected $2,211 from ticket sales. This can be represented by this system of equations
84c + 157d = 2,640
67c + 134d = 2,211
A. What could the equation 17c + 23d = 429 mean in this situation?

B. The solution to the original system is the pair c = 9 and d = 12. Explain why it makes sense that this
pair of values is also a solution to the equation 17c + 23d = 429.