The library sells 500 books at its annual used-book fundraiser. They take in a total of $3940. Children's
books cost $5, and adult books cost $9. How many
children's books did they sell?
Let e = number of children's books sold, and Let
a= the number of adult books sold.
Which system of equations can the librarians use to
solve this problem?
A.
5c+9a=500
c+a=3940
c+a=500
C.
5c+9a=3940
B.
a=500-c
9c+5a=3940
a+c=500
D.
5a+9c=3940