SOLUTION: 5. SALES TAX Amelia received a gift card to a local music shop for her birthday. She plans to use the gift card to buy some new CDs. a. Amelia chose 3 CDs that each cost $16.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: 5. SALES TAX Amelia received a gift card to a local music shop for her birthday. She plans to use the gift card to buy some new CDs. a. Amelia chose 3 CDs that each cost $16.      Log On


   

Question 920417:
5. SALES TAX Amelia received a gift card to a local music shop for her birthday. She plans to use the gift card to buy some new CDs.
a. Amelia chose 3 CDs that each cost $16. The sales tax on the three CDs is $3.96. Write a direct variation equation relating sales tax to the price.


b. Graph the equation you wrote in part a.


c. What is the sales tax rate that Amelia is paying on
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
direct variation equation is y = kx
k is the constant of variation.

amelia bought 3 cds at 16 apiece for a total of 48 dollars.

the tax was 3.96.

the direct variation equation of y = kx becomes 3.96 = k * 48

solve for k to get k = 3.96 / 48 which is equal to .0825.

the direct variation equation of y = kx becomes y = .0825 * x

that is the equation that you graph.

the graph of that equation is shown below along with the value of y when x = 48.

the value of y = 3.96 as it should be.

$$$