Andrea purchased 10 packs of trading cards online and received a 20% discount off each pack. Shipping cost $3.99. Write an algebraic expression to represent the total cost of the trading cards with the shipping cost, if x represents the cost of each pack of cards.

Cost of 1 pack of trading cards = xTotal packs purchased = 10Cost of 10 packs before discount (A) = 10 * xDiscount percentage = 20 %Discount amount per pack = (20/100) * xDiscount amount for 10 packs (B) = (20/100) * x * 10Cost of 10 packs after discount is (A) - (B) = (10 * x) - ((20/100) * x * 10) Simplifying, we get x * (10 - 200/100) = x * (10 - 2) = x * 8 = 8 * xCost of shipping = $3.99Total cost of 10 packs of trading cards after discount and including cost of shipping can be represented by the algebraic expression 8 * x + 3.99 or 8x + 3.99