Jason and Brittany are saving up to go on a trip together at the end of the summer. Jason had $12 at the beginning of the summer and makes $42 a day at the grocery store. Brittany had $68 at the beginning of the summer, but she is helping her aunt who is paying her $35 a day to help in his mechanic shop. Find the system of equations to represent this situation. Use the substitution method with that system to determine after how many days of working will they have the same amount of money. On that day how much money will they each have?