Sydney needs to earn $35 so she can buy her father a birthday present. Her mom said she can make $6 per hour cleaning around the house and $5 per hour raking leaves. There are 6 hours available before Sydney's father's birthday party where she can either clean or rake leaves. Which system of equations can be used to find how many hours Sydney should spend cleaning and raking leaves so that she will earn exactly enough money to buy her father a birthday present? Let x represent the number of hours spent cleaning and y represent the number of hours spent raking leaves.