So firstly, we have to find the LCD, or lowest common denominator, of 9 and 7. To do this, list the multiples of 9 and 7 and the lowest multiple they share is going to be your LCD. In this case, the LCD of 9 and 7 is 63. Multiply x^2/9 by 7/7 and 2y/7 by 9/9:

Next, add the numerators together, and your answer will be: 
Answer:
Sam had 80 dollars in his pocket. He was feeling generous, so he handed out equal amount of money to each of his friends. After he handed out the money, he had 53 dollars left. How much did Sam give out to each one of his friends?
Step-by-step explanation:
In this real-world problem, the money he had at the beginning resembles the 80 in the equation. The -3x is the money he gives out to each of his friends. The 53 on the right-hand side is the money he has left after he gives the money away.
To find out how much money Casey and her two friends will each get, we simply need to divide the total amount of income by the amount of people receiving a part of it
54 / 3 = 18
Casey and her two friends each got $18 from their lemonade stand.
Hope that helped! =)
See the attached picture for the answers: