Question

Grant is a member of a book club. He pays a $10 yearly membership fee and can purchase books through the club for $2.75 each. His total annual cost is a function of the number of books, b, that he purchases in a year: C(b) = 2.75b + 10   What is the total cost if he purchases 13 books in a year?

Answer 1

$45.75 because you take the 2.75 and times it by how may books which is 13 and you get $35.75 then you add your $10 and it will give you $45.75

Answer 2

2.75b+10 (write the equation)
2.75(13)+10 (substitute for b)
35.75+10 (multiply)
45.75