How do you write algebraic expressions to model quantities?

Let's say you are walking down the street and you see a lemonade stand. One of the workers tell you that if you buy a lemonade you will have to buy 5 times that amount to sit down and a lemonade cost $2. you order 2 lemonades. after grabbing your drink you feel like sitting down. so you go up to the stand and and attempt to purchase a seat.
5($2x2)=x
(THIS IS JUST AN EXAMPLE)