Question

Jalissa bought a backpack for $30 and n notebooks for $2.50 each.

a. Write a function that shows the amount Jalissa spent on her backpack and n notebooks.
b. If she spent $40, how many notebooks did she buy?

Answer 1

f(n) = 2.50n + 30....f(n) also represents y...so if u wanted to write y = 2.50n + 30...it would be the same.

if she spent 40....

40 = 2.50n + 30
40 - 30 = 2.50n
10 = 2.50n
10/2.50 = n
4 = n.....so she bought 4 notebooks

Answer 2

y=2.5x+30 - the function where y = the total cost and x = the # of notebooks.

40 = 2.5x + 30 - Plug 40 into y and solve
10= 2.5x
x = 4, the number of notebooks she bought