Eli goes to a restaurant and the subtotal on the bill was xx dollars. A tax of 5% is applied to the bill. Eli decides to leave a tip of 18% on the entire bill (including the tax). Write an expression in terms of xx that represents the total amount that Eli paid.

Answer 1

To calculate the total amount that Eli paid, we can break it down step by step.

1. Calculate the tax on the subtotal: The tax is 5% of the subtotal \( xx \). \[ \text{Tax} = 0.05 \cdot xx \]

2. Calculate the total bill including tax: The total bill is the subtotal plus the tax. \[ \text{Total Bill} = xx + (0.05 \cdot xx) = xx + 0.05xx = 1.05xx \]

3. Calculate the tip on the total bill: The tip is 18% of the total bill (which includes tax). \[ \text{Tip} = 0.18 \cdot (1.05xx) \]

4. Calculate the total amount paid: The total amount Eli pays is the total bill plus the tip. \[ \text{Total Amount Paid} = \text{Total Bill} + \text{Tip} = 1.05xx + 0.18(1.05xx) \]

   Now we simplify this expression: \[ \text{Total Amount Paid} = 1.05xx + 0.189xx = (1.05 + 0.189)xx = 1.239xx \]

So, the expression that represents the total amount that Eli paid is: \[ \boxed{1.239xx} \]