13.

A pair of shoes costs $52.99 and the state sales tax is 8%. Use the formula C = p + rp to find the total cost of the shoes, where C is the total cost, p is the price, and r is the sales tax rate.

1 answer

To find the total cost of the shoes using the formula \( C = p + rp \), we will follow these steps:

  1. Identify the variables:

    • \( p \) (price of the shoes) = $52.99
    • \( r \) (sales tax rate) = 8% = 0.08 (as a decimal)
  2. Calculate the sales tax amount (\( rp \)): \( rp = r \times p = 0.08 \times 52.99 \)

    \[ rp = 0.08 \times 52.99 = 4.2392 \]

    Rounding to two decimal places (since we're dealing with currency), the sales tax is approximately $4.24.

  3. Now, calculate the total cost \( C \): \[ C = p + rp = 52.99 + 4.24 \]

    \[ C = 57.23 \]

Therefore, the total cost of the shoes is $57.23.