Question

The library sells 376 books at its annual used-book sale. The sale takes in a total of $2119. Children's books cost $4, and adult books cost $7.

Let x = number of children's books sold, and let y = the number of adult books sold.

Which system of equations can the librarians use to model this situation?

Answer 1

system of equations are

`x+y=376`

`4x+7y=2119`

Explanation:

Let x = number of children's books sold,

and let y = the number of adult books sold

The library sells 376 books at its annual used-book sale

so, we get equation as

`x+y=376`

Children's books cost $4

So, total cost of children book is 4x

adult books cost $7

So, total cost of adult book is 7y

so, we get total cost is 4x+7y

he sale takes in a total of $2119

so, we get equation as

`4x+7y=2119`

so,

system of equations are

`x+y=376`

`4x+7y=2119`