You can write an expression to represent the total cost of a pair of shoes. The price of the shoes is the variable r. The shoes are marked down 20% or 0.2r. So the new price of the shoes will be r - 0.2r. You will also have to pay a tax of 5% or 0.05 of the new price. This is written as 1.05(r - 0.2r). You can simplify it by doing whats in the parenthesis.
