Answer the questions below in the spaces provided where appr…

Answer the questions below in the spaces provided where appropriate.  Show ALL work and proper units.   While checks are only being marked for certain questions, I would highly recommend that you do them whenever you can, as it will serve as proof to yourself that you have the correct answer! No work shown results in a mark of zero!

Jodi wants to buy a book that costs $18 before taxes. The ta…

Jodi wants to buy a book that costs $18 before taxes. The taxes are 13% HST.a)  Write an equation for the total cost, C, after taxes for a book that costs r dollars.  [2]b)  Find the total cost of the book after taxes.  [1]c)  Suppose the cost of another book after taxes is $36.80.  What was the total cost of the book before taxes?  [2]