Theo wants to buy a pair of roller blades that originally cost 49.99. if they are on sale for 25% off and theo must pay 5.5% sales tax, what amount will theo pay for the blades

First calculate the sale price.
 Since they are 25% off, he is paying 75% of the original price.
 Multiply 49.99 by 75% ( 0.75) for the sale price.

49.99 * 0.75 = 37.49 ( amount the roller blades are on sale for)
 Now multiply the sale price by 5.5% (0.055) to find the amount of tax, then add that to the sale price:

37.49 x 0.055 = 2.06

37.49 + 2.06 = $39.55 total cost.