First of all: subtract 3 from 3x then from 2y then divide
The question is "What's Stella's opportunity cost of working on her serve for an hour?" The rest of the info looks like it's meant to confuse you. They charge $10 an hour. She values an hour of her time at $20. I believe that means she would pay $20. Hope this helps!
Answer:
Josh sold all of his collectable baseball cards (n), for $2 each. After selling them all he counted his money and he had $18. How many baseball cards did Josh sell?
