Answer:
$34.88
Explanation:
If the discount is 20%, then the sale price is 80% of the full (original) cost:
0.80($40.00) = $32.
Sam has to pay 9% sales tax on this $32. The total cost of his order would then be 1.09($32) = $34.88. If desired, you could write this as the equivalent $32 + 0.09($32).