Answer:
$171
Step-by-step explanation:
Price of lemonade = $9 per cup
Quantity sold = 19 cups of lemonade
Revenue = price of the product × quantity of the product sold
Silvia's total revenue = price × Quantity
= $9 × 19 cups
= $171
Silvia has made a total of $171 from selling 19 cups of lemonade at $9 each