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?

system of equations are

Step-by-step 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

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

so,

system of equations are

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !